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Open Questions — Research Index

A living, human-curated index of outstanding unknowns across the Open Enzyme wiki, organized by topic. The index documents open questions — it does not try to resolve them. Resolution happens via the validation experiments, primary research, and future sweep passes.

How this differs from synthesis/

Document Generated by Purpose Cadence
synthesis/ Sweep daemon (Pass 1 + Pass 2), user-annotated Cross-doc action queue; "what to do next" — new connections, contradictions, proposed experiments Appended every sweep; pruned manually by Brian
open-questions.md (this doc) Human-curated, gathered from compound/concept page "Open Questions" sections Standing index of what we don't yet know, organized by topic; cross-references to the source pages where each question is elaborated Updated when a new open question is surfaced, or when one is resolved

In short: synthesis/ is a rolling action queue; open-questions.md is a stable map of known unknowns. An item resolved in synthesis/ (architecture: synthesis/README.md) may remove its corresponding entry here; a newly-discovered unknown surfaced by a wiki page update gets added here.

Uricase / Enzyme Engineering

Questions about uricase variant selection, GI survival, protease resistance, yeast-vs-koji choice, and expression strategy.

Variant selection and properties

  • Is Candida utilis uricase substantially more amenable to oral delivery than A. flavus uricase? Three programs (Allena/ALLN-346 and two others per industry-revealed preference) picked C. utilis over A. flavus. Driver could be: (a) higher specific activity, (b) better protease resistance, © fewer anti-drug-antibody concerns, (d) IP/freedom-to-operate. See uricase-variant-selection.md, synthesis archive 2026-04-23 gout-clinical-pipeline.
  • No human trial data exists for A. flavus uricase delivered orally. ALLN-346 (C. utilis) showed no systemic immune response, but fungal-vs-bacterial immunogenicity differences in the gut lumen are uncharacterized. See uricase-variant-selection.md §7.
  • Vibrio vulnificus uricase expression in S. cerevisiae: codon optimization and titer remain unknown. Likely feasible from sequence analysis; no peer-reviewed titer in eukaryotic hosts. See uricase-variant-selection.md.
  • Rasburicase's anti-drug-antibody profile in ~60% of patients on IV delivery: does oral mucosal delivery invert this via oral tolerance? Open — oral tolerance literature suggests yes, but uricase-specific data is absent. See engineered-yeast-uricase-proposal.md §6 Q5.

GI survival and stability

  • Refolding kinetics of acid-unfolded uricase are unknown. The enzyme's tetramer dissociates at low pH; whether it refolds after duodenal pH normalization determines real-world efficacy beyond simple in vitro survival measurements. See gi-survival-prediction.md §§refolding.
  • Does rice bran substrate improve or degrade uricase GI survival? Rice bran contains phytic acid, phenolics, and fiber — could stabilize the tetramer (polyphenol-tetramer binding) or destabilize it (altered transit time). See engineered-koji-protocol.md, synthesis archive Connection 7.
  • Secretion vs. intracellular expression in yeast — which gives better effective dose? Intracellular accumulation gives cell-wall acid protection (~10-15% survival advantage) but limits total enzyme output. Secreted is efficient but acid-vulnerable. See engineered-yeast-uricase-proposal.md, synthesis archive Contradiction 2.

Wild-type koji baseline and EPI applications

  • What is the quantitative enzyme activity of shio-koji (units/g) vs. commercial PERT (Creon, Zenpep units per pill)? Lab-measurable via amylase / protease / lipase assays of finished shio-koji, but not yet done. This is the key comparison that determines whether wild-type koji is a meaningful PERT-reducer or merely a condiment. Methodology now specified in enzyme-quantification-protocol.md — Tier 3 bench first-run (~$200–400 reagents, single-day session at a community-college lab) is the load-bearing experiment. See also koji-home-fermentation.md. (source: koji-home-fermentation.md, enzyme-quantification-protocol.md)
  • Is shio-koji-marinated protein a meaningful PERT-reducer in mild-to-moderate EPI? N=1 / household trials with PERT-dose-per-meal tracking would generate informative observational data. No formal evidence exists. See koji-home-fermentation.md. (source: koji-home-fermentation.md)
  • What is the gastric survival of shio-koji-derived enzymes? Hypothesis: poor without enteric coating; useful only for pre-digestion in marinade phase, not in-gut activity post-ingestion. Testable via simulated gastric fluid (SGF pH 2, pepsin, 2h). See koji-home-fermentation.md. (source: koji-home-fermentation.md)
  • Is lipase the limiting digestive-enzyme axis for fat malabsorption EPI when using wild-type A. oryzae shio-koji? Lipase activity of A. oryzae shio-koji is low compared to A. niger or engineered strains. Quantitative comparison needed. Methodology in enzyme-quantification-protocol.md §3.1 (p-NPP lipase assay vs. Creon-cap-equivalent reference standard). See also koji-home-fermentation.md, aspergillus-oryzae.md. (source: koji-home-fermentation.md, enzyme-quantification-protocol.md)
  • Are there any human studies of koji-fermented diets in EPI specifically? None identified. Would be high-value evidence. See koji-home-fermentation.md. (source: koji-home-fermentation.md)

Yeast vs. koji platform choice

  • Does the yeast mass-burden problem (50-170 g fresh yeast/day for a therapeutic dose) rule out yeast as a primary platform? Koji is dose-advantaged on scaling; 10-15 g dry koji = equivalent enzyme load. See engineered-yeast-uricase-proposal.md §5, synthesis archive Contradiction 1.
  • Can the Ward 1995 A. awamori glucoamylase-fusion + KEX-2 architecture (>2 g/L submerged) transfer to solid-state rice koji fermentation? The submerged-culture precedent is solid (PMID 9634791). Solid-state mass transfer, redox, and proteolysis dynamics are different. This is the specific gating experiment for the lactoferrin co-expression module. See engineered-koji-protocol.md §16, spm-resolution-pathway.md §5.

Protein engineering

Genotype stratification of the gut-lumen sink response

  • RESOLVED 2026-05-08 per comp-019: The gut-lumen uricase mechanism does NOT depend on Q141K-positive disease-state vulnerability. Phase A literature mining surfaced ZERO Q141K-stratified uricase trials in any language — the Q141K × allopurinol response literature is rich (Wallace 2018, Vora 2021, Stamp 2019), the Q141K × uricase response literature is empty. Phase B flux model anchored against Miyazaki 2025 (PMID 40033341, first direct human in-vivo measurement of jejunal urate secretion stratified by ABCG2 functional class) predicts WT/WT males show the LARGEST ΔSUA (−0.83 mg/dL at 25 mg/day, 90% CI −1.13 to −0.57), Q141K homozygotes the smallest among typical-genotype patients (−0.50 mg/dL), severe ABCG2 dysfunction (Q126*+Q141K compound) the smallest of all (−0.28 mg/dL — structural ceiling but applies to a small subset). Mechanism is multiplicative on residual ABCG2 capacity. Strain-engineering implication: substrate-limited regime confirmed (capacity ratios 32–1300×) — yield target stays at 25 mg/dose; engineering binding constraint is GI-survival, not enzyme yield. Phase 2b RCT design implication: typical-gout cohort with Q141K + Q126* as stratification variables, NOT enrichment criteria. See comp-019 page and cross-validation.md Claim 1 (rating updated 6/10 → 6.5/10).
  • Remaining open: does the flux-model-predicted ΔSUA in non-Q141K patients hold up in a Phase 2b RCT? The flux model is prospective, not validated. Specific magnitudes (−0.5 to −1.0 mg/dL band) are hypotheses pending clinical data. See validation-experiments.md for the wet-lab dependencies.

Co-engineered substrate-supply mechanisms

Strategic question across the engineering pipeline: should the chassis produce both substrate-degradation (uricase) AND substrate-supply enhancement (ABCG2 induction or relief of ABCG2 suppression) in a single product? Genotype-agnostic by design — the Q141K rescue mechanism in abcg2-modulators.md §6 is one of the things this approach handles gracefully, but the engineering target is "boost intestinal urate secretion across populations," not "fix a specific variant." (2026-04-28 — Brian) Reinforced post-comp-019 2026-05-08 — the flux model confirms the gut-lumen sink works across genotypes; rescue interventions ADD to (don't replace) the sink mechanism.

Three candidate routes surfaced so far, each with a different chassis-level implication:

  • Butyrate co-production or co-formulation with a butyrogenic strain. Colonic butyrate hits both wild-type ABCG2 (PPARγ induction; Xie 2020 PMID 32555444) AND the Q141K variant (HDAC-mediated trafficking rescue; Basseville 2012 PMID 22472121) — dual-mechanism substrate-supply enhancement. A koji co-formulated with Faecalibacterium prausnitzii or similar butyrate producer, or engineered to overproduce butyrate from a heterologous pathway, would deliver supply enhancement alongside uricase degradation. Mechanistic Extrapolation; engineering feasibility unassessed. See abcg2-modulators.md §Engineering implications #2.

  • Glucoraphanin co-production (Nrf2 → ABCG2 induction). Already flagged at abcg2-modulators.md §Engineering implications #1. Sulforaphane precursor produced in the chassis, converted to active sulforaphane by gut myrosinase from cruciferous-resident bacteria. Mechanistic Extrapolation; A. oryzae glucoraphanin biosynthetic pathway feasibility not yet assessed — multi-enzyme plant pathway, fungal-host expression unknown.

  • Lactoferrin co-expression (relief of TNFα-driven ABCG2 suppression). Already in flight as engineered-koji-protocol.md §16 for its primary CP1a/CP5b roles. Beyond those: sustained lactoferrin secretion in the lumen would suppress local TNFα → relieve the parallel ABCG2 suppression mechanism (Ferrer-Picón 2020, PMID 31211831). The lactoferrin module may be doing more for the gut-sink than its current positioning suggests — secondary effect not yet quantified.

Decision-gate framing: a chassis that produces uricase + supply-enhancer is two products in one — substrate supply increased AND substrate degradation increased, with potential super-additive serum-UA effect. Engineering effort approximately doubles vs. uricase-alone; clinical effect plausibly more than doubles. The right time to decide is when uricase-alone Phase 1 efficacy data is in — compare predicted uricase + supply-enhancer effect size to the marginal engineering cost. Until then, the question is "is this a first-class platform target, or a downstream optimization?"

See abcg2-modulators.md, gut-lumen-sink.md, engineered-koji-protocol.md.

NLRP3 / Gout Biology

Questions about chokepoint biology, priming mechanisms, species-gap caveats, and biomarker interpretation.

Priming and upstream signals

  • Is complement C5a activation necessary or sufficient for MSU-triggered NLRP3 priming in clinical gout flares, or is TLR4/LPS still dominant in real patients? Cumpelik 2016 (PMID 26245757) and Khameneh 2017 (PMID 28167912) are animal model + in vitro; human C5a-priming dominance remains to be confirmed in vivo. (2026-04-24 Pass 2 — new addition) See complement-c5a-gout.md §6, nlrp3-exploit-map.md.
  • Are there patient subgroups where non-complement priming (true LPS from SIBO) dominates? Would change stack selection per patient. See complement-c5a-gout.md §6 Q5.
  • Is TNFSF14/LIGHT elevation a universal feature of gout flares or a patient subtype? Would a TNFSF14 biomarker identify responders to EGCG or CERC-002 better than generic hs-CRP? (2026-04-24 Pass 2 — new addition) See tnfsf14-gout-target.md.
  • Does lactoferrin-based CP5b engagement eliminate the CP0 priming signal, or only suppress downstream? See complement-c5a-gout.md §4 Q4.

Chokepoint biology

  • Does engineered-koji prophylaxis reduce flare frequency on ULT initiation? This is the clinical question that justifies the platform's "adjunct" positioning. Colchicine is the current standard for ULT-initiation prophylaxis (ACR 2020: 0.5–0.6 mg/day × 3–6 months). A food-based CP1a-targeted koji adjunct could plausibly reduce the frequency of colchicine-rescue or prednisone-rescue events during the dissolution-flare window. Flare-rate endpoint, measurable in any ULT-initiation cohort with adequate follow-up. (Mechanistic Extrapolation; source: colchicine.md §8)
  • CP1a + CP2/CP3 synergy in vitro. Is there a measurable synergy between kojic acid (CP1a) and colchicine (CP2/CP3) in suppressing MSU-induced IL-1β release in primary monocytes? A bead-MSU stimulation assay with combinatorial dosing would answer this. (Mechanistic Extrapolation; source: colchicine.md §8)
  • CP5b — why do gout patients' SPM levels remain low during flare? Dietary precursor shortage, 15-LOX expression defect, or demand outpacing production? See spm-resolution-pathway.md §6 Q1.
  • ALX/FPR2 polymorphisms in gout. Are there FPR2 genetic variants associated with flare severity or tophi formation? See spm-resolution-pathway.md §6 Q2.
  • Direct SPM bioassay feasibility. SPM measurement requires LC-MS/MS at pg/mL. Practical for clinical biomarker stacks, or research-only? See spm-resolution-pathway.md §6 Q3.
  • Does aggNET-mediated C5a sequestration feed back to CP0? The resolution loop may close on itself (SPM → aggNET → C5a sequestration → reduced priming). Mechanistic elegance suggests yes; direct evidence is thin. See spm-resolution-pathway.md §6 Q4.

Chokepoint candidates surfaced by comp-014 (2026-05-06)

  • Does ADA (adenosine deaminase) warrant formal addition as a named gout chokepoint? ADA catalyzes adenosine → inosine in purine catabolism upstream of XO. comp-014 Phase 2 (6,798 fungal compounds) identified ADA as a target with fungal-compound coverage via GLPP (G. lucidum) and cordycepin + native pentostatin (C. militaris). Pending Phase 3-6 comp-014 follow-ups for formal admit/reject decision. See medicinal-mushroom-compound-mapping-computational.md, gout-pathophysiology.md §ADA. (Mechanistic Extrapolation; source: medicinal-mushroom-compound-mapping-computational.md)
  • Does PINK1/mitophagy warrant formal addition as a named gout chokepoint? PINK1 senses mitochondrial damage and recruits Parkin to initiate mitophagy, clearing damaged mitochondria before they generate the mtROS that triggers NLRP3 (CP2). NLRP3-priming-adjacent — operates upstream of CP2. comp-014 Phase 2 identified fungal compounds with PINK1-modulating activity. Pending Phase 3-6 comp-014 follow-ups for formal admit/reject decision. See medicinal-mushroom-compound-mapping-computational.md, gout-pathophysiology.md §PINK1. (Mechanistic Extrapolation; source: medicinal-mushroom-compound-mapping-computational.md)

Chokepoint candidates and sub-questions surfaced by comp-018 (2026-05-08)

comp-018 — Upstream Complement Modulator Sweep (committed 2026-05-08, on feature branch pending PR) confirmed direct natural-product C5aR1 antagonist class triply-empty (comp-014 + §1.21 + comp-018), but found a substantial dietary / fungal / FDA-approved-drug literature one node upstream at C3 convertase (rosmarinic acid TIER-1 dietary, luteolin triple-mechanism, etc.). Two open follow-ups surfaced:

  • Are there compounds that upregulate the host-side complement regulators (Factor H, DAF/CD55, CD59, clusterin, CR1) — proteins that protect host cells from complement attack — and would such compounds provide a fundamentally different mechanism for CP0 closure? comp-018 Phase 1's brief explicitly included regulator-expression upregulation in the target list, but the results came back direct-inhibitor-dominant; the expression-modulation thread is largely unanswered and worth a focused Phase 2 sub-task. The question is mechanistically distinct: direct inhibition reduces convertase activity acutely, while regulator upregulation is a chronic, transcriptionally-mediated mode of action that may behave differently in a gut-mucosa context (sustained dietary exposure → durable Factor H upregulation → chronic CP0 dampening). Anchor any Phase 2 answer to expression datasets (GTEx, HPA, GEO microarray) plus complement-functional assays — gene upregulation alone wouldn't prove C3/C5 convertase suppression in vivo. (Source: 2026-05-08 sweep Open Question 2 + Pass 3 augmentation; queued as comp-018 Phase 2 sub-task; synthesis archive 2026-05-08 Item 9.)
  • Anchor compound classes worth checking: plant-derived Nrf2 activators (sulforaphane, curcumin, EGCG — already in supplements-stack), butyrate (HDAC inhibitor, plausible Factor H induction), retinoids, dietary polyphenols generally. Cross-applies to the food-grade HDACi screen (comp-007) — HDAC inhibitors that surfaced for ABCG2 derepression may also induce complement-regulator expression.

  • Cross-references: complement-c5a-gout.md (Factor H, DAF/CD55, CD59, clusterin biology), comp-018 (the parent breadth scan), hypotheses/H05-daf-scr14-cp0-thesis.md (engineering-side DAF thread — engineered koji that secretes the DAF protein is a distinct mechanism from compounds that upregulate endogenous DAF expression).

  • Should "upstream-CP0" be formally promoted to a new chokepoint class (CP-1, going further upstream) or kept as scope-expansion of CP0? comp-018 proposes scope-expansion (working term: "upstream-CP0") with the rationale that the priming chokepoint is unitary at the mechanism level (C5a generation) and subdividing CP0 into "downstream-CP0" (C5aR1 antagonism) vs "upstream-CP0" (everything proximal) reads cleanly within the existing framework. CP-1 would imply a fundamentally different priming mechanism, which isn't the case. Final naming decision is the user's; this question is queued until enough operational substance accumulates around CP0 to make the naming load-bearing. (Source: comp-018 §"Chokepoint-class naming proposal"; 2026-05-08 sweep Connection 2 / Item 2.)

  • What is the quantitative relationship between dietary rosmarinic acid intake (rosemary, lemon balm, spearmint, salvia, mentha) and gut-luminal + plasma rosmarinic acid concentrations? The load-bearing PK question for the dietary CP0 thread. comp-020 documented a 44× IC50 spread across published assay formats (34 µM optimal per Englberger 1988 → 137–182 µM per Cimanga 1999 / Mu 2013); separately, human bioavailability data exists in Baba 2004 / Konishi 2005 / Nakazawa 1998 but the dietary-source → gut-luminal concentration → plasma Cmax chain is wide and incompletely characterized. Without a PK anchor, the "dietary CP0 coverage via rosmarinic acid" claim is mechanistically grounded but quantitatively unanchored. Partially consumed by comp-029 (2026-05-16): comp-029 used the IC50 distribution + bioavailability ranges with explicit uncertainty bounds, and the resulting YELLOW combined-CP0 verdict is partly attributable to the rosmarinic acid uncertainty (Spearman r = −0.658 for IC50 — the dominant sensitivity driver). comp-029 didn't resolve the open question; it consumed the uncertainty productively. Resolution path: human PK study of rosmarinic acid from dietary sources (single-dose, n=6–12, plasma + urine sampling over 24h) — proposed cost ~$15–25K. Partner / clinical-tier work, not OE-direct. Tightening comp-029's input range with measured PK data could flip the combined-CP0 verdict from YELLOW to GREEN. Until then, the dietary rosmarinic acid thread carries an explicit "PK unresolved" caveat per complement-c5a-gout.md §9.7 and upstream-complement-verification-rerun-computational.md. (Source: 2026-05-15 sweep Open Question 1; comp-020 documents the 44× spread; comp-029 documents the YELLOW combined-CP0 verdict.)

  • Can the genotype-informed supplement quantification workflow be validated in a small multi-user pilot (N=5–10) before the larger H09 community-fermentation trial? The genotype-informed-supplement-workflow page (promoted from self-experiment-protocol.md §12 on 2026-05-16) names the five-step closed-loop pipeline (genotype → variant-informed selection → produce/source → Tier 2 batch QC → calibrated dose → biomarker tracking) and is currently instantiated at n=1. H09 — Community Fermentation Reliability explicitly depends on multi-user batch consistency, not single-user feasibility — so an N=5–10 pilot of the workflow itself, before any community-fermentation infrastructure is committed, would surface operational failure modes (user error in Tier 2 assays, batch CV exceeding the ±20% Tier 2 tolerance, genotype misclassification from consumer panels). Cost: ~$2,000–5,000 (genotyping + reagents + coordination). Practical constraints: real human-subjects work → IRB consideration (low-risk self-experimentation pilots may qualify for exemption, but multi-user data collection probably needs IRB review); recruitment (5–10 motivated participants willing to clinical-grade-genotype + run a stack + report biomarker data); coordination overhead. The genotype-informed-supplement-workflow.md "Open follow-ups → Multi-user pilot validation" subsection already names this pilot as the natural next-step gate before H09. (Source: 2026-05-15 sweep Open Question 3; workflow page Phase 2 follow-up.)

Species-gap and translation

  • Does the 1,000× dapansutrile mouse-vs-human cellular IC50 gap apply to every mouse-derived NLRP3 potency claim in the wiki? Oridonin, BHB, ursolic acid, β-caryophyllene, carnosine — all have murine efficacy as primary evidence. Translation risk is now the dominant uncertainty. See nlrp3-inhibitor-screen.md ChEMBL appendix, synthesis archive 2026-04-23 nlrp3-inhibitor-screen.
  • For "pathway modulator" class (quercetin, ursolic acid, BHB, KPV, carnosine, taurine), what's the correct primary-evidence yardstick? ChEMBL IC50 doesn't exist by definition for these compounds. Is it functional IL-1β suppression in MSU-stimulated human macrophages? See synthesis archive 2026-04-23 Open Questions.

Biomarker interpretation

Compound-Specific Questions

Organized by compound. Each bullet summarizes the question; cross-links point to the page where it is elaborated.

EGCG

  • Is the 86 nM proteasome IC50 reached at physiological green-tea doses? At 0.1-0.3% oral bioavailability, unformulated green tea probably can't hit the threshold; phytosome formulations (5-10% bioavailability) plausibly can. Central translation question. See egcg.md Open questions #1.
  • Proteasome vs. IKK dose-response. If the reframe is correct, IκBα stabilization tracks proteasome IC50 (86 nM), IKK activity requires ≥10 μM. A dose titration with both readouts falsifies or confirms. See egcg.md Open questions #2.
  • Hepatotoxicity mechanism. Proteasome-driven, redox-driven, mitochondrial, or immune-mediated? Literature divided; practical dose cap (600 mg/day) is conservative enough to cover all. Mechanism informs formulation choice. See egcg.md Open questions #3.
  • Does EGCG suppress TNFSF14 at the HVEM-receptor level specifically, or only through general NF-κB blockade? Replication needed in human macrophages. See egcg.md Open questions #4, validation-experiments.md §1.8.
  • Can DHA + EGCG achieve combined TNFSF14 suppression? Orthogonal mechanisms; both already in stack. See egcg.md Open questions #5.

Quercetin

BHB / Ketones

  • Does the ketogenic-diet-gout rat result translate to a human oral BHB dosing regimen? The rat study used intrinsic ketogenesis (diet); exogenous BHB dosing has different PK. See bhb-ketones.md, nlrp3-exploit-map.md.
  • Does BHB's mouse-vs-human species gap follow the dapansutrile pattern? Mouse ketogenic data may overstate BHB's required human dose. See synthesis archive 2026-04-23 Connection #2.

Lactoferrin

  • Can lactoferrin be expressed in A. oryzae at therapeutically relevant titers in solid-state rice fermentation? P. pastoris 3.5 g/L and A. awamori >2 g/L are both submerged culture. Solid-state koji is the missing data point. (2026-04-24 Pass 2 — new addition; feasibility check found strong Aspergillus submerged-culture precedent, so the remaining question is specifically the submerged→solid-state transfer.) See engineered-koji-protocol.md §16, spm-resolution-pathway.md §6 Q6.
  • Does A. oryzae KEX-2 process a glucoamylase-lactoferrin fusion identically to A. awamori? Critical for transferring the Ward 1995 architecture. See engineered-koji-protocol.md §16 Risks.
  • Is there a dedicated gout trial of oral lactoferrin anywhere? None identified. See spm-resolution-pathway.md §6 Q5.
  • Bovine vs. human lactoferrin — which is the right GRAS-pathway variant? Bovine has infant-formula history; human has the Aspergillus expression precedent. See engineered-koji-protocol.md §16.

Carnosine

  • Human gout RCT evidence is absent. Hyperuricemia rat dual-phenotype data is promising; translation to human serum uric acid / flare reduction is unknown. See carnosine.md Open questions.
  • Engineered yeast carnosine titer (~150 mg/L baseline) needs primary-source confirmation. Carried from internal analysis without cited peer-reviewed titer. See carnosine.md Open questions, engineered-koji-protocol.md §15.
  • Koji carnosine co-expression feasibility. No published carnosine-in-koji data; target is mechanistic extrapolation. See engineered-koji-protocol.md §15, validation-experiments.md §1.24.
  • Serum carnosinase (CN1) half-life limits. Whether rapid cleavage caps peak systemic exposure below effective NLRP3-suppression concentration in humans is unresolved. Carnosinase-resistant analogs (D-carnosine, N-acetyl-carnosine) not yet gout-tested. See carnosine.md Open questions.
  • Carnosine + uricase co-delivery: additive, synergistic, or flat? Complementary mechanisms (renal URAT1/GLUT9 vs. luminal urate degradation). See carnosine.md Open questions.
  • Androgen + carnosine combined experiment not yet run. The "precision countermeasure" framing in koji-endgame-strain.md §2.5 composes two Animal Model links (androgen → URAT1↑ in one set of experiments; carnosine → URAT1↓ in a different set). A combined experiment — hyperuricemia rat on androgen supplementation + carnosine co-treatment vs. androgen alone — would directly confirm or falsify the precision-countermeasure claim. (Mechanistic Extrapolation; source: koji-endgame-strain.md §2.5)

Zileuton

  • Does zileuton (5-LOX inhibitor) abort or shorten gout flares in any case series or retrospective data? Asthma patients who also have gout = natural population to query. (2026-04-24 Pass 2 — new addition.) See synthesis archive 2026-04-24 Open Questions, validation-experiments.md §3.9.
  • What's the theory of action beyond 5-LOX? Any secondary effects (redox, cytokine-modulation, neutrophil-direct) that could be advantageous or detrimental in gout context? Dossier in progress.

Tier-4 inhibitor screen — missed gout-model data (largely closed 2026-04-23 + 2026-05-05; one residual gap)

  • Original framing: Do any other Tier-4 compounds (limonene, alpha-pinene, sulforaphane, omega-3 metabolites, EGCG/curcumin variants) have published MSU/gout animal-model data that the keyword-gated original screen missed? β-Caryophyllene was originally Tier 4 "no gout evidence" but a 2021 MSU rat paper surfaced and forced the re-rank.
  • 2026-04-23 audit (executed): EGCG → Tier 2; limonene → Tier 3 supplement / Tier 4 production; sulforaphane → Tier 2–3 supplement / Tier 4 production. New methodological standard added to scripts/sweep-prompt.md (Pass 2 must check MSU animal models, hyperuricemia rat models, human-cell NLRP3 assays, and Nrf2/NF-κB sub-μM activity for every compound — not just those with "gout" in the title).
  • 2026-05-05 follow-up audit (executed via PubMed full-text + bioRxiv):
  • Sulforaphane: upgraded from Tier 2–3 to Tier 2 with two additional citations — Yang 2018 Rheumatology PMID 29340626 (oral SFN attenuated MSU foot-pad and air-pouch acute gout in mice) and Greaney 2015 J Leukoc Biol PMID 26269198 (Nrf2-independent inflammasome inhibition + in vivo gout peritonitis). Three independent in vivo gout-relevant readouts now cited.
  • Theaflavins: added as a new Tier 2 supplement candidate (was not in the wiki at all; see theaflavins.md). Direct MSU peritonitis Animal Model + multi-transporter URAT1/GLUT9/OAT modulation distinct from EGCG.
  • α-Pinene: confirmed no direct MSU/gout animal-model data exists; Tier 4 ranking stands.
  • d-Limonene: Venkatesan 2025 already cited (PMID 41515190); no further re-rank.
  • Omega-3 metabolites (RvD1, MaR1, etc.): already cited in spm-resolution-pathway.md; no new data.
  • Residual gap: Curcumin variants (tetrahydrocurcumin, BCM-95 formulation, curcumin analogs) returned 11 PubMed hits on the 2026-05-05 audit; none surfaced as direct MSU/gout animal-model evidence beyond what's already in the curcumin coverage. A targeted full-text-grep audit specifically for curcumin derivative activity in MSU-gout would close this last sub-question. Likely low-yield.

See nlrp3-inhibitor-screen.md §Meta-Finding, synthesis archive 2026-04-23 cannabinoids-terpenes Connection #2, theaflavins.md. - Would THCV's 20× higher CB2 affinity (Ki 7.5 nM vs. BCP 155 nM) translate to better MSU gout efficacy if dose-bridged? Untested. THCV has cannabis-derived regulatory friction so this is academic unless BCP underperforms in a planned MSU macrophage assay. See cannabinoids-terpenes.md, synthesis archive 2026-04-23 cannabinoids-terpenes Open Questions. - Is there an engineered microbial route to β-caryophyllene that scales past 10–50 mg/L? Current titers are two orders of magnitude below the likely therapeutic dose (rat 100–400 mg/kg ≈ 1.1–4.5 g/day BSA-scaled). Titer improvement is required before "engineered koji produces BCP" enters the platform thesis. See cannabinoids-terpenes.md, synthesis archive 2026-04-23 cannabinoids-terpenes Open Questions.

Beta-caryophyllene

  • Does oral BCP at 50-200 mg/day (supplement range) reproduce the 100-400 mg/kg rat MSU effect? PK scaling suggests possible 20-50× dose gap. Resolvable with desk work before wet-lab. See cannabinoids-terpenes.md, synthesis archive 2026-04-23 cannabinoids Open Questions.
  • Would THCV's 20× higher CB2 affinity (Ki 7.5 nM) translate to better MSU gout efficacy? Untested; regulatory friction makes it academic unless BCP underperforms. See cannabinoids-terpenes.md.
  • Engineered microbial route to β-caryophyllene past 10-50 mg/L titer? Two orders of magnitude below therapeutic dose. Titer improvement would unlock the "koji produces BCP" pathway. See cannabinoids-terpenes.md.

Oridonin

  • Does oridonin's cellular-vs-kinetic IC50 split (5.18 μM human THP-1 per ChEMBL) matter for gout-specific efficacy? No gout-specific studies exist for oridonin. Covalent Cys279 binding may be mechanistically preserved across species. See oridonin.md, synthesis archive 2026-04-23 Connection 3.

Other compounds (aggregated)

  • ChEMBL cross-check sweep on remaining stack compounds (BHB, KPV, ursolic acid, taurine, sulforaphane, berberine, resveratrol, curcumin, ergothioneine, ferulic acid, kojic acid): 2-5 more mechanistic reframings are expected when primary curated bioactivities are compared to the current wiki mechanism claims. See synthesis archive 2026-04-23 Connection 4.

Chaperone framework α-coefficient generalization — two-fold-class calibration vs. arbitrary novel-fold secreted disulfide-rich payloads (added 2026-05-15)

  • Does the chaperone-orthogonal-stacking.md framework's α-coefficient calibration generalize beyond the two fold classes covered by the §3.5.4 calibration set (lactoferrin transferrin-lobe + DAF SCR1-4 CCP/SCR)? The framework derives α coefficients from non-koji in vitro folding kinetics and structural-rigidity arguments (Notari 2023; Schmidt 2010); §1.9 + §1.25 will validate the two specific fold classes empirically, but a successful calibration does NOT generalize the framework to future secreted disulfide-rich payloads with different fold architectures — e.g., C1-INH serpin (the parallel CP0 candidate flagged in comp-018 Phase 2), recombinant antibody-derived constructs, or other novel-fold secreted enzymes. Per Pass 3 of the 2026-05-15 sweep: cytosolic-payload novel folds (complestatin NRPS modules, cytosolic biosynthesis pathways) are NOT affected — the α framework only covers ER-pathway PDI-load competition, so cytosolic payloads sidestep the question entirely.
  • Two resolution paths:
  • Calibration-set breadth expansion — add a third / fourth fold class to the §3.5.4 calibration set (cost: ~$3–5K + 8 weeks wet-lab per additional fold class). Linear scaling; each new fold class validates its α independently.
  • Direct PDI-residence-time assay in A. oryzae microsomes — multi-year tool-build that would generalize across fold classes simultaneously. No published A. oryzae-specific PDI kcat data exists for any fold class as of 2026-05-06. Tool-build cost not yet scoped.
  • Fires when: OE wants to commit a new secreted disulfide-rich payload to a cassette design (e.g., C1-INH for the parallel CP0 track, an antibody-derived construct, or any future ER-routed cassette) and the framework's α prediction is the load-bearing decision input. Cytosolic payloads (cordycepin / carnS / panD / native ergothioneine biosynthesis) bypass this question entirely per the koji-endgame-strain.md §3 third-cassette slot design rule. Until then, dormant.
  • Cross-references: chaperone-orthogonal-stacking.md §8 item 6 "Generalization caveat (added 2026-05-15)" (canonical home of the caveat); chaperone-orthogonal-stacking.md §3.5.4 (the two-fold-class calibration set definition); validation-experiments.md §1.9 + §1.25 (the calibration arms themselves); H05 — DAF SCR1-4 CP0 thesis (uses the framework as load-bearing).

Quantification methodology — Tier 2 inter-operator reproducibility (added 2026-05-15)

  • Can the quantification-ladder.md Tier 2 assays stay within their pre-registered tracking tolerance (±20% per the ladder's calibrate-once-at-Tier-3 / track-batches-cheap operational pattern) when run by multiple independent home / community-biolab operators after a shared Tier 3 calibration? The framework is specified; no multi-operator reproducibility data exists. Per Pass 3 review of the 2026-05-14 Open Question 1 sweep item — which mis-cited H06 Dimension 2's ±15% threshold (Dimension 2 specifies that for Tier 3 HPLC/MS, not Tier 2) — the narrower question is the right framing. Applies to:
  • Ergothioneine (SOP-6 Ellman's reagent / DTNB) — well-anchored chemistry but multi-operator data lacking
  • GLPP (SOP-6 phenol-sulfuric) — same
  • Cordycepin (SOP-6 diazo-coupling, Speculative) — the method validity question is the upstream gate; tracked at validation-experiments.md §1.28. The inter-operator reproducibility question fires only after §1.28 returns GREEN.
  • Uricase activity (enzyme-quantification-protocol.md, 293 nm UV absorbance) — same multi-operator gap
  • Fires when: Tier 2 assays start being used in practice by ≥3 independent operators (home + community-biolab adopters); structural prerequisite for the H09 — Community Fermentation Reliability batch-CV claim (CV < 30% cross-user requires both producer + assay-runner reproducibility). Until then, dormant. Resolution work: design a small multi-operator round-robin (single calibrated reference batch sent to N=3–5 operators, each runs the Tier 2 assay independently, compare results) — estimated $500–1,000 + 4–6 weeks once operator network exists.
  • Cross-references: H06, H09, quantification-ladder.md, medicinal-mushroom-extract-sops.md SOP-6, enzyme-quantification-protocol.md, self-experiment-protocol.md §12 (the workflow that depends on this).

Platform / Strategic

Questions about the koji-first vs. yeast-first choice, community fermentation reliability, strain stability, regulatory positioning, and the overall platform thesis.

Layered intervention — combining a compounded repurposed-drug pill with the engineered-koji daily food (added 2026-05-15, dormant until both upstream products exist)

The compounding-pharmacy track and the engineered-koji daily-food track target non-overlapping chokepoints and use non-overlapping consumption modes. A combined intervention would deliver:

  • Compounded pill (Rx, daily) — hits CP6a (5-LOX, via zileuton) or CP6b (GSDMD, via disulfiram) — see compounding-pharmacy-track.md §"Combined / hybrid candidates"
  • Engineered-koji daily food (shio-koji / amazake / miso) — hits CP0 (luminal uricase) and upstream priming (CP1–CP5) — see koji-endgame-strain.md

The combination is mechanistically clean (different mechanisms, different routes), but no co-administration protocol or patient-experience model exists:

  • What's the timing relationship between the pill and the food? Does enzyme activity in the gut lumen affect drug absorption? Do gut-microbiota changes from daily fermented food alter drug PK?
  • What does the daily patient experience look like (pill + condiment + food prep + monitoring)? Adherence-friendly or burdensome?
  • What endpoints + biomarkers would actually let us measure layered effect vs. either track alone?
  • Off-target interactions: any reasonable drug-food interaction concerns at therapeutic doses?

Fires when: (a) the compounding-pharmacy track's first prescription pathway opens for a discovery-engine candidate (disulfiram is the lead — see comp-027 brief on disulfiram dose modeling) AND (b) the engineered-koji strain becomes available (Phase 0 currently — neither the §1.9 dual-cassette koji nor a community-college-lab proxy exists yet). Until both upstream gates clear, the co-administration protocol is dormant — drafting it now would be path-dependent speculation about two products that don't exist.

Cross-references: compounding-pharmacy-track.md §"Combined / hybrid candidates" (originating mention), koji-endgame-strain.md, comp-027 (disulfiram dose modeling), synthesis/done/2026-05-13-open-question-1-can-the-compounding-pharmacy-tracks-repurposed-drug.md (originating sweep item).

Riskiest assumption #2 — can engineered koji be reliably home- and community-fermented at therapeutic doses? (added 2026-05-15, the platform's #2 load-bearing scientific bet — production/delivery side)

Falsification card committed: H09 — Community Fermentation Reliability (stub, 2026-05-15). Full killshot menu, pre-committed thresholds, and assumption stack queued as Phase 2 on the H09 card.

Sister risk to H08 (mechanism side). The platform thesis has two equally load-bearing risks: even if the gut-lumen mechanism works (H08), the platform's distinctive accessibility thesis ("grow it at home like sourdough") rests on this assumption (H09). If H09 dies, the platform collapses to "centrally-manufactured oral enzyme with a non-traditional supply chain" — defensible but no longer open-source-accessible.

The corpus offers strong mitigation sketches (chromosomal integration, first-batch QC, never-backslop-past-N rule) and honest framing (cross-validation.md Claim 5 calls "Easy as Sourdough" the most audacious and least-validated platform claim), but zero direct empirical evidence for an engineered multi-cassette A. oryzae strain in the community-fermentation context. Ward 1995 §1.9 dual-cassette feasibility test is the first wet-lab gate — but only validates lab expression, not community-fermentation reliability.

Provisional alive/killed thresholds: CV < 30% cross-user enzyme activity, strain retention ≥ 95% at generation 5, contamination < 5% per batch under hygiene protocol. Killed if a properly-powered multi-user pilot materially misses any of these.

Phase 2 follow-ups (queued on H09 card, see full table there): - P2-1 Lit scan: industrial koji batch-CV baseline (Japanese miso/sake reproducibility data) - P2-2 Multi-user community-fermentation pilot trial (N=5–10, central QC at community biolab) - P2-3 Passaging-based strain stability protocol (50 generations, qPCR/activity readout) - P2-4 Drying activity-retention comparison (lyophilization vs. oven-dry vs. trehalose-lyoprotected) - P2-5 Contamination-spike test (wild-strain spike, 5-generation tracking) - P2-6 Smartphone-camera colorimetric uric-acid assay validation - P2-11 Regulatory framework scoping pass (engineered-spore distribution path) — user-action-required (external consultant engagement)

Cross-references: cross-validation.md §Claim 5 (3/10 → 6/10 reframe), open-source-platform.md §"Open Questions — Reliability of Community Fermentation", engineered-koji-protocol.md, koji-endgame-strain.md, self-experiment-protocol.md (Brian's n=1 home-fermentation data point), operations/ward-1995-lab-access.md (note: at operations/, not wiki/), synthesis/done/2026-05-13-riskiest-assumption-1-the-single-load-bearing-belief-in-the-current-platform.md (originating sweep item).

Riskiest assumption #1 — does the gut-lumen uricase sink produce a clinically meaningful SUA reduction in typical (non-CKD) gout? (added 2026-05-15, the platform's #1 load-bearing scientific bet — mechanism side)

Falsification card committed: H08 — Gut-Lumen Sink Platform Thesis (stub, 2026-05-15). The full killshot menu, pre-committed thresholds, and assumption stack are queued as Phase 2 on the H08 card.

The platform's load-bearing belief is that the gut-lumen sink produces a clinically meaningful SUA reduction in a typical (non-CKD) gout cohort, in the −0.5 to −1.0 mg/dL band predicted by the comp-019 flux model. The biology is sound (ABCG2 secretes ~33% of daily UA elimination into the gut lumen; comp-019's flux model is internally consistent against Miyazaki 2025 measurements) but the clinical-translation link is unvalidated:

  • ALLN-346 Phase 2a Study 201 showed signal in CKD patients; Study 202 (broader cohort) showed 0–5% reduction, no significance vs. placebo, and the program terminated with 19/200 enrolled.
  • Zero uricase trials (ALLN-346, PRX-115, rasburicase, pegloticase) have stratified by ABCG2 Q141K genotype — the Q141K × allopurinol response literature is rich, the Q141K × uricase response literature is empty.
  • The comp-019 flux model is prospective and unvalidated against any human cohort.

If the typical-gout effect is <0.5 mg/dL, the platform collapses from "core mechanism" to "mild adjunct" — reshaping commercial framing, self-experiment framing, and the priority of peer tracks (LBP, siRNA/URAT1, medicinal-mushroom-complement).

Phase 2 follow-ups (queued on H08 card): - P2-1 — Lit scan for any post-ALLN-346 oral or gut-targeted uricase Phase 2 typical-gout readout (Opus subagent). - P2-2 — Re-analysis attempt of ALLN-346 Study 202 cohort-level genotype data accessibility (FOIA / sponsor request / supplementary data grep). Highest information-per-dollar killshot if data obtainable. - P2-3 through P2-6 — Populate assumption stack, killshot menu, pre-committed thresholds, failure-mode coverage map per H01 template. - P2-7 — Integrate n=1 self-experiment design with the FEUA protocol on self-experiment-protocol.md.

Cross-references: cross-validation.md §Claim 1 (feasibility 6.5/10), gut-lumen-sink.md, uricase.md, uricase-abcg2-genotype-stratification-computational.md (comp-019), synthesis/done/2026-05-09-riskiest-assumption-1*.md (originating sweep item).

Genotype stratification — Q141K and the gut-lumen-sink mechanism's responder population (added 2026-05-08, highest-priority open question for the platform's primary demographic)

  • Can the gut-lumen uricase sink produce meaningful SUA reduction in non-Q141K males, or does the mechanism rely on Q141K-positive disease-state ABCG2 vulnerability to show benefit? This is the single most important unanswered question for Open Enzyme's primary demographic positioning. If the mechanism only works in Q141K-positive readers (~25-30% of European-descent men, ~50%+ of East Asian men), the platform's addressable population shrinks dramatically — from "all gout patients" to "Q141K-positive gout patients." That's a strategic question that should change trial design, demographic targeting, and possibly commercial framing. (Source: surfaced 2026-05-08 sweep Open Question 1; comp-017 + cross-validation.md prior-art context; synthesis archive 2026-05-08 Item 8.)
  • Path 1 — comp-019 (in-silico, $0, 2-4 weeks). Two-phase: (A) literature stratification mining of ALLN-346 / PRX-115 / rasburicase clinical data + GWAS by Q141K status; (B) first-principles flux model of intestinal urate flux predicting ΔSUA per genotype × dose scenario. Spawned as background Opus subagent 2026-05-08 — results pending. Cheapest answer-moving move; same shape as comp-017.
  • Path 2 — §1.27 Caco-2 transwell wet-lab gate (gated on comp-019 signal). Caco-2 monolayer with apical uricase + basolateral urate. Vary ABCG2 expression (siRNA knockdown, Q141K mutant transfection). Measure apical urate flux. Cost ~$5-10K, 6-8 weeks. Direct test of whether ABCG2 capacity is rate-limiting. Triggered if comp-019 Phase B's flux model predicts genotype-conditional benefit.
  • Path 3 — n=1 stratified self-experiment (parallel, low-friction). Brian + contributors with known genotype (via personal-genome-protocol MinION or 23andMe import) take shio-koji or future engineered koji + monitor SUA. Stratify post-hoc by Q141K status. Weak power per individual, but if the platform builds a contributor cohort with genotype data, it's the lowest-cost path to real human evidence. Lives in self-experiment-protocol.md once cohort exists.
  • Path 4 — Consumer genomics partnership / natural-experiment data (long shot). 23andMe, AncestryDNA, or other consumer-genomics platforms could potentially surface a small cohort of gout patients with self-reported uricase exposure (allopurinol-failed patients trialing rasburicase IV, plus any existing oral-uricase trial participants who released their data). Long-shot partnership move; not load-bearing unless someone offers it.
  • Cross-references: comp-017 (intestinal ABCG2 sex-dimorphism), comp-016 (T × intestinal ABCG2 evidence mining), cross-validation.md (gut-lumen uricase mechanism currently rated 6/10), gut-lumen-sink.md, abcg2-modulators.md, personal-genome-protocol.md, hypotheses/H07-clomid-intestinal-er-antagonism.md (related mechanism question).

Platform selection and thesis

  • Is Open Enzyme's wiki-wide IC50 provenance practice rigorous enough? Many IC50 values come from review papers, not primary ChEMBL-indexed assays. A written standard would prevent legacy-citation drift. See synthesis archive 2026-04-23 Open Questions.
  • Does MCC950 / CRID3 / CP-456773 absence from ChEMBL name search reflect a curation gap or a synonym issue? Worth a direct structure-based query. See synthesis archive 2026-04-23 Open Questions.
  • Is there a "ChEMBL blind spot" for natural products? ChEMBL's curation bias favors medicinal chemistry literature; natural products with strong functional but weak binding data (BCP, BHB, many terpenes) may be systematically underrepresented. See synthesis archive 2026-04-23 Open Questions.

Novel modalities (from modality-chokepoint-matrix.md)

The Modality × Target Matrix (2026-04-28) surfaces ten high-leverage exploration vectors not currently in the OE wiki. The highest-priority open questions per the matrix:

  • siRNA against URAT1 mRNA via kidney-tropic conjugate. Sequence-specific renal-reabsorption knockdown; cleaner off-target profile than benzbromarone-class uricosurics. Adjacent to inclisiran-style GalNAc conjugate precedent. Zero clinical programs for gout. (Mechanistic Extrapolation; source: modality-chokepoint-matrix.md)
  • Engineered Faecalibacterium prausnitzii for local butyrate at the gut crypt. Hits both wild-type ABCG2 (PPARγ) and Q141K (HDAC trafficking rescue) per abcg2-modulators.md. Durable colonization avoids the "eat koji daily" adherence problem. (Mechanistic Extrapolation; source: modality-chokepoint-matrix.md)
  • Myeloid-tropic LNP delivering NLRP3-silencing mRNA/siRNA to vessel-wall macrophages. Brian-pattern Lp-PLA2 persistence is the n=1 case study. Acuitas/Moderna myeloid LNPs exist for oncology; gout repurposing is novel. (Mechanistic Extrapolation; source: modality-chokepoint-matrix.md)
  • Pharmacological chaperone for ABCG2 Q141K folding rescue. CFTR-corrector class precedent (~$10B annual market for ΔF508 correction). Same ATP-binding cassette superfamily. Academic mechanism literature exists (Basseville 2012 PMID 22472121); no clinical programs. (In Vitro; source: modality-chokepoint-matrix.md, abcg2-modulators.md)
  • mRNA-IL-1RA pulse therapy for acute flare termination. Transient expression matches flare window. Zero programs; mechanistically defensible; competes with canakinumab on cost. (Mechanistic Extrapolation; source: modality-chokepoint-matrix.md)
  • Wearable sweat-based or microneedle continuous UA monitoring. Changes intervention-titration kinetics. UCSD/Stanford research-stage. (Mechanistic Extrapolation; source: modality-chokepoint-matrix.md)

Engineered LBP chassis (peer track to koji)

The Engineered LBP Chassis page (committed 2026-05-05 as scope-page in response to 2026-05-05 sweep Open Question #3) formalizes engineered obligate anaerobes (Faecalibacterium prausnitzii primary, Akkermansia muciniphila, Bacteroides) as a peer track to the koji chassis. Six discrete in silico follow-ups are queued — none requires pharma-partner involvement to start:

  • P2-1 — Lit scan: F. prausnitzii engineering state-of-the-art. Genetic toolkit maturity, heterologous payload titers achieved, gap to therapeutic-grade. (Queued, Opus subagent.)
  • P2-2 — Lit scan: commercial / clinical engineered-LBP landscape. Synlogic, Vedanta, NextBiotix, Seres, Pendulum — programs, partnership / licensing profile. (Queued, Opus subagent.)
  • P2-3 — Lit scan: FDA LBP regulatory path. 2018 guidance, Vowst precedent, IND-enabling package, timeline + capital. (Queued, Opus subagent.)
  • P2-4 — comp-008: F. prausnitzii heterologous expression feasibility. Tracked in computational-experiments.md Planned Analyses. (Queued, Sonnet subagent.)
  • P2-5 — Falsification card H02. Stub committed at hypotheses/H02-engineered-lbp-thesis.md; full population queued.
  • P2-6 — Comparative chassis matrix for gout indication. F. prausnitzii vs. Akkermansia vs. Bacteroides vs. engineered E. coli Nissle — payload tractability, niche fit, engineering complexity.

Phase 3 (content-triggered, not calendar-triggered): platform-framing reflection — does the LBP track justify expanding Open Enzyme's framing from "engineered enzymes in koji" to "solve gout, every avenue, fully open"? Reflection note queued in open-enzyme-vision.md.

Purine-Degrading Bacteria (PDB) — gut as independent urate disposal organ (added 2026-05-15)

Full page: purine-degrading-bacteria.md. The 2,8-dioxopurine pathway (Liu et al. 2023 Cell + 2025 Nat Microbiol) establishes ~15–25% of gut bacteria as a functionally distinct urate disposal system that evolved to compensate for hominid uricase loss. Engineered EcN with the full gene cluster (CBT2.0) achieved −63% plasma UA in hyperuricemic mice. Five priority follow-up threads:

PDB-Q1 — Quantitative SUA reduction from PDB restoration in humans with intact renal function. The FARMM study (n=30) had no statistical power to detect serum urate changes, and subjects had normal kidneys. What is the mg/dL effect in a typical gout patient? This number gates whether PDB restoration is "adjunctive to pharmacotherapy" or "potentially standalone." Required before designing any PDB clinical trial. No lit scan will resolve this — it requires a prospective study. Frame as a priority gap, not a computation. (Human RCT or n-of-1 cohort; no current data)

PDB-Q2 — Does PDB-derived butyrate at physiological gut concentrations activate ABCG2 via PPARγ? The butyrate → PPARγ → ABCG2 mechanism is established at pharmacological doses and for dietary fiber effects (DASH RCT, Li 2023 PMID 36948133). Whether native PDB flux generates enough luminal butyrate to meaningfully activate this axis is unresolved. This is a tractable Caco-2 experiment: measure ABCG2 expression in enterocyte monolayers at the butyrate concentrations achievable via gut PDB fermentation vs. pharmacological sodium butyrate doses. Estimated cost: $2,000–5,000 if a wet-lab partner has Caco-2 capability. (In Vitro; immediately testable)

PDB-Q3 — Selenium status and gut PDB function in humans. DOPDH (the key PDB enzyme) requires selenium and runs 27x faster with selenium than the sulfur-dependent variant. Liu et al. 2025 cites correlations between lower urinary molybdenum and higher serum urate / gout incidence; the selenium arm of this is implied but uncharacterized. Immediate personal action: add serum selenium to next blood panel. If Brian's selenium is low-normal, supplementation (55–200 µg/day, safe range, $0.10/day) could activate latent PDB capacity without any bacterial intervention. A lit scan for "serum selenium × serum urate × gut metagenomics" in existing biobank cohorts could be run as a subagent task in a few minutes. (Mechanistic Extrapolation; trivial personal test)

PDB-Q4 — Is yanthine (2,8-dioxopurine) measurable on any commercial panel? Yanthine is elevated in gout patients vs. healthy controls (Life Metabolism 2025, n=68) — it is the first PDB pathway intermediate, and elevated serum yanthine = PDB insufficiency. If there is a commercial metabolomics panel or specialty lab offering yanthine measurement, adding it to Brian's next self-experiment draw would answer whether his gut PDB are functionally depleted. This is a $200–400 metabolomics panel question, not a $10K research study. Lit scan to identify: does Metabolon Precision Metabolomics, Genova NutrEval, or similar measure yanthine / 2,8-dioxopurine? (Human biomarker; immediate triage task)

PDB-Q5 — Dual-chassis EcN design: add the PDB gene cluster to the PULSE uricase system. CBT2.0 demonstrated the full 8-gene PDB cluster is expressible in E. coli (Life Metabolism 2025). The PULSE system already uses EcN for gut-lumen uricase delivery. Combining them — EcN expressing both uricase AND the 2,8-dioxopurine pathway — creates a dual-mechanism organism hitting urate degradation via two independent pathways while SCFA outputs compound the effect via ABCG2. The primary engineering barrier is DOPDH: a selenoprotein requiring SelD (selenophosphate synthase), which EcN carries natively. A Phase 1 lit scan on "DOPDH heterologous expression in E. coli" + review of CBT2.0's expression construct would establish whether the PULSE + PDB combination is a near-term or long-term engineering target. (Mechanistic Extrapolation + Animal Model precedent; lit scan feasibility ~30 min subagent)

See engineered-lbp-chassis.md (LBP chassis peer track), gut-lumen-sink.md (PULSE/uricase context), abcg2-modulators.md (butyrate/PPARγ + A. indistinctus/hippuric acid axes).

TCM × Modern Rigor — discovery-engine output (fourth peer-track exploration vector)

The TCM × Modern Rigor scope page (committed 2026-05-05) formalizes traditional Chinese medicine materia medica as a discovery-engine output — applying a six-rule methodology lens (chokepoint mapping, ChEMBL cross-check, bioavailability-honest framing, formula decomposition, standardized-extract specification, falsification-card discipline) to TCM compounds with documented gout/hyperuricemia indications. Sister to the LBP chassis and siRNA/URAT1 peer tracks. Six in silico Phase 2 follow-ups queued — none requires pharma-partner involvement to start:

  • P2-1 — Lit scan: classical TCM gout formulas + modern Chinese clinical evidence. Si Miao San family, Bai Hu Jia Gui Zhi Tang, Smilax-enhanced variations. Global multilingual sources by default — ChiCTR registry, CNKI/WanFang (Chinese-language papers, read in original), J-STAGE (Japanese Kampo medicine literature), PubMed (English cross-check only). Output: evidence-tier-tagged summary of which formulas have credible clinical signal vs. tradition-only. (Queued, Opus subagent.)
  • P2-2 — comp-011: ChEMBL cross-check of the 8 candidate TCM gout compounds. Same framework as comp-004 (supplement ABCG2 antagonism). Inputs: Smilax glabra, Rheum officinale, Plantago asiatica, Phellodendron amurense, Polygonum cuspidatum, Cinnamomum cassia, Atractylodes macrocephala, Astragalus membranaceus. Targets: NLRP3, ABCG2, URAT1, GLUT9, XO, NF-κB pathway. Output: per-compound mechanism + curated bioactivity + chokepoint hit map + IC50 vs. achievable gut-luminal concentration. (Queued, Sonnet subagent.)
  • P2-3 — Lit scan: Smilax glabra (Tu Fu Ling 土茯苓) deep-dive. Highest-leverage single compound — explicit primary gout herb in classical TCM with substantial modern Chinese clinical literature. XO inhibition kinetics, uricosuric mechanism, standardization issues, drug interactions, adverse effects. (Queued, Opus subagent.)
  • P2-4 — Lit scan: Si Miao San multi-component coverage analysis. Decompose the four-herb formula (Phellodendron, Atractylodes, Achyranthes, Coix) per "formula decomposition" discipline. Map each component to chokepoints. Identify designed-coverage vs. redundant vs. synergistic design. (Queued, Opus subagent.)
  • P2-5 — Falsification card H04: TCM × rigor methodology lens. Stub committed at hypotheses/H04-tcm-rigor-intersection.md; full population queued. (Stub committed; full population queued.)
  • P2-6 — Bioavailability characterization for top 3 compounds advancing from P2-2. Quantitative oral bioavailability + gut-vs-systemic distribution + first-pass metabolism + microbiome metabolism. Maps to the "embrace gut-luminal mechanisms" discipline (rule #3). (Queued, Opus subagent.)

Phase 3 reflection (content-triggered, not calendar-triggered): does the TCM-rigor track accumulate enough substance to elevate from "methodology lens" to "first-class discovery-engine output named in open-enzyme-vision.md §2.2 alongside the repurposing-surface candidates"? Trigger: after P2-1 through P2-6 land.

Medicinal mushroom complement — Phase 7 peer track (cultivation, not engineering)

The Medicinal Mushroom Complement Track scope page (committed 2026-05-06) formalizes native-compound medicinal mushrooms (Ganoderma lucidum GLPP, Cordyceps militaris cordycepin+pentostatin, Pleurotus citrinopileatus ergothioneine, Lentinula edodes eritadenine, Hericium erinaceus erinacines, Trametes versicolor PSK, Inonotus obliquus inotodiol) as a peer track to engineered koji / engineered LBPs / siRNA discovery. Different engineering discipline (cultivation + extraction, NO genetic engineering); different consumption UX (decoction / tincture / dried fruiting body vs koji condiments); regulatory simplicity (GRAS food / supplement-grade, no GMO burden). Seven Phase 7 follow-ups status per scope page §6:

  • #1 Strain selection lit scan ✅ (multilingual, 2026-05-06; outputs: Ganoderma / Cordyceps / Pleurotus per-species scan files in comp-014 outputs dir)
  • #2 Cultivation × yield meta-analysis ✅ (2026-05-06)
  • #3 Extract characterization SOPs — stub at medicinal-mushroom-extract-sops.md (SOP-1 GLPP gated on Phase 5b CNKI dive; SOP-3 EGT lowest-friction)
  • #4 GLPP+cordycepin synergy wet-lab gate — stub at validation-experiments.md §2.6 (4-arm: whole-fermentate / cordycepin / cordycepin+GLPP / cordycepin+pentostatin)
  • #5 H06 hypothesis card ✅ (stub at hypotheses/H06-medicinal-mushroom-complement-track.md)
  • #6 Modality-chokepoint-matrix native-compound row ✅ (2026-05-06)
  • #7 Therapeutic dose grounding pass (added 2026-05-06; expanded 2026-05-06 to also cover colorimetric-assay precedent literature) — for each load-bearing compound (cordycepin, GLPP, ergothioneine, eritadenine, erinacines, PSK, inotodiol, astilbin), grep-verify the human therapeutic dose range from primary clinical / supplement-trial literature under the pre-commit grep-verify gate. The track currently discusses production yields without a dose-context anchor — without that anchor, "GYS60 hits 7,883 mg/L" is meaningless to a supplement-stack decision and to the wet-lab-gated Phase 2 follow-ups. Cross-applies to the TCM compound triage compounds. Output: per-compound dose-grounding table (typical supplement / clinical-trial / mechanism-derived ranges, with confidence tier). Sub-task: while in primary literature, also note validated colorimetric-assay precedents at ~Tier 2 sensitivity per medicinal-mushroom-extract-sops.md SOP-6 — specifically whether a diazo-coupling cordycepin assay exists (current SOP-6 flags this as Speculative); Ellman's-for-EGT and phenol-sulfuric-for-total-polysaccharide are already well-anchored.

CTO-actionable TODOs are tracked operationally — see operations/todos.md §"Phase 7 medicinal-mushroom-complement track" (TODO surface; this index points to it for completeness per the umbrella aggregation pattern).

Phase 3 reflection (content-triggered, not calendar-triggered): does the medicinal-mushroom-complement track justify expanding Open Enzyme's framing from "engineered enzymes in koji" to include native-compound producers as first-class platform contribution? Likely yes given the regulatory simplicity + home-fermentability + multi-compound-per-species advantages, but defer formal reflection until SOP-3 (EGT) lands as proof-of-concept.

siRNA against URAT1 — discovery-engine output (peer-track exploration vector to LBP)

The siRNA / URAT1 modality page (committed 2026-05-05 as scope-page in response to 2026-05-05 sweep Priority Action #3) formalizes kidney-tropic siRNA against URAT1 mRNA as a discovery-engine output — non-fermentable, non-microbial, positioned for partner / spinout development rather than in-house manufacture. Sister to the LBP chassis under the broader chase-every-avenue framing. Six in silico Phase 2 follow-ups queued — none requires pharma-partner involvement to start:

  • P2-1 — Lit scan: kidney-tropic conjugate chemistry state-of-the-art. Megalin-binding peptides, CDP nanoparticles, kidney-cortex-selective LNPs, aptamer-siRNA chimeras — design space, current best titers / pharmacokinetics, IP landscape. (Queued, Opus subagent.)
  • P2-2 — comp-009: URAT1 mRNA structural analysis for siRNA target site selection. Tracked in computational-experiments.md Planned Analyses. (Queued, Sonnet subagent.)
  • P2-3 — Lit scan: commercial / clinical landscape for kidney-tropic siRNA programs. Alnylam, Arrowhead, Dicerna / Novo Nordisk, Sirnaomics — non-gout indications and what transfers; partnership / licensing profile. (Queued, Opus subagent.)
  • P2-4 — Comparative analysis: siRNA vs. small-molecule URAT1 inhibitors (pozdeutinurad / AR882 efficacy, safety, cost, durability, hormone-axis-interaction). Honest competitive 5–10 year horizon assessment. (Queued.)
  • P2-5 — Falsification card H03. Stub committed at hypotheses/H03-sirna-urat1-thesis.md; full population queued.
  • P2-6 — Lit scan: FDA siRNA regulatory path. Inclisiran / patisiran precedent, IND-enabling package, ballpark timeline + capital for a kidney-tropic siRNA BLA. (Queued, Opus subagent.)

Phase 3 reflection (shared with LBP track and rolled into the same Strategic Reflections Queue entry in synthesis/): does the discovery-engine track accumulate enough substance to formally rebrand Open Enzyme as "open-source gout-solving research project" rather than "open-source koji-engineered enzyme library"?

Ward 1995 §1.9 — global lab-access landscape

The Ward 1995 §1.9 Lab Access — Global Landscape scope page (committed 2026-05-05) maps parallel options for executing validation-experiments.md §1.9 across Japan, China, and Europe. Key findings:

  • NSlD-ΔP10 (the ten-protease-deletion chassis required for H01 Killshot #1) is not deposited in any public culture collection. The Maruyama lab at the University of Tokyo is the only verified source. (source: ward-1995-lab-access-global.md)
  • Single most actionable lead: Jun-ichi Maruyama (amarujun@mail.ecc.u-tokyo.ac.jp), University of Tokyo, origin lab for NSlD-ΔP10. Draft email included in the scope page.
  • Parallel paths if Tokyo doesn't engage: Jingwen Zhou / Guoqiang Zhang group at Jiangnan University (C19 chassis, multi-locus integration); Mortensen group at DTU (CRISPR-Cas9/Mad7 toolkit, strongest in Europe).
  • Order-of-operations: Week 0 email Maruyama + Jiangnan in parallel; Week 2 email DTU if no response; Week 4 query JCM/CGMCC for substitute strains; Week 6 reframe as paid CRO request.

This is an active-search resource, not a static reference; expect updates as outreach lands. (source: ward-1995-lab-access-global.md)

Community fermentation and strain stability

  • Does engineered koji drift across generations of home propagation? Food-grade strains carry no antibiotic selection marker (correct for GRAS compliance), which removes the pressure that keeps the construct in the population. Chromosomal integration + redundant copies mitigate but don't eliminate. See open-source-platform.md §Open Questions.
  • Do 100 home fermenters of the same koji strain get consistent enzyme titers and NLRP3 activity? Home conditions ≠ lab conditions. Protocol robustness is the gating question for the decentralized vision. See open-source-platform.md §Open Questions, synthesis archive Open Question 3.
  • Is distribution of engineered spores "drug manufacturing" (requires IND) or "research strain" (flexible)? Regulatory question with large downstream implications. See open-source-platform.md §Open Questions.

Regulatory

  • Is an engineered-yeast food product a food (GRAS self-determination), a dietary supplement (DSHEA), or a Biologic License Application? FDA's evolving live-biotherapeutic-products (LBP) framework may apply. See engineered-yeast-uricase-proposal.md §6 Q4.
  • Does the canakinumab approval (Aug 2023) create demand for a cheaper IL-1β blocker reachable via food-grade engineering? Canakinumab at $300K/year is the price ceiling; anything food-grade clears cost bar. Question is whether food-grade compounds can produce clinically meaningful IL-1β suppression. See synthesis archive 2026-04-23 gout-clinical-pipeline Open Questions.

Microbiota and safety at scale

  • Does daily high-enzyme + NLRP3-inhibitor load select for specific commensals or cause dysbiosis? Repeated-dose koji is effectively a selection-pressure experiment on gut flora. See cross-validation.md, synthesis archive Connection 8, synthesis archive Open Question 1.
  • Do any commensals express uricase natively? If yes, does engineered uricase suppress or enhance them? See synthesis archive Connection 8.
  • For Brian's n=1 self-experiment specifically — what microbiome red flags would matter? Scope clarification (2026-04-27): the platform is not chasing regulatory approval; the question is what to monitor in Brian's self-experiment to detect dysbiosis early enough to course-correct. Candidate panel: stool 16S at baseline + week 4/8/12, watch for alpha-diversity drop >20%, C. difficile / Enterococcus expansion, fecal calprotectin elevation, persistent stool-form change. A full safety cohort (n=8) is out of scope for a self-experiment; the n=1 monitoring panel is the right resolution. Tracked separately in self-experiment-protocol.md. See synthesis archive Connection 8.

Combination therapy

  • Could engineered koji become standard adjunct to allopurinol? ALLN-346 trial demonstrated enzyme-adjunct efficacy on stable allopurinol. Complementary mechanisms (XO upstream, luminal-degradation downstream). See synthesis archive Open Question 2.

Safety / Self-Experiment

Questions about biomarker interpretation, red-flag thresholds, and microbiome impact specifically in Brian's n=1 protocol.

Biomarker design

Red-flag thresholds

  • What LFT elevation threshold triggers zileuton discontinuation? Zyflo label guidance exists (AST/ALT >3× ULN); Brian-specific thresholds for the off-label protocol should match. See validation-experiments.md §3.9.
  • What biomarkers signal microbiome disruption vs. acceptable variation? Alpha diversity drop threshold, specific pathobiont expansion (e.g., Clostridium difficile, Enterococcus), inflammatory markers (fecal calprotectin). See cross-validation.md.
  • Is BCP dose-scaling from 100-400 mg/kg rat MSU to 50-200 mg/day supplement safe to extrapolate upward? If supplement is 20-50× under-dosed, bumping the dose has unknown off-target profile in humans. See cannabinoids-terpenes.md.

Data handling

  • How should Brian's and Lynn's lab data be handled in the Open Enzyme repository? PII concerns for self-experiment data make public-GitHub inappropriate. Needs a data-handling framework (private repo, anonymized public summary, or external store with controlled access). (2026-04-24 Pass 2 annotation — flagged for brainstorm.)

Recent additions (2026-04-24 Pass 2)

These are the five open questions Brian annotated during the 2026-04-24 synthesis Pass 2. They are also listed above in their topical sections; consolidated here as the day's output.

  1. Is complement activation (C5a) necessary or sufficient for MSU-triggered NLRP3 priming in clinical gout flares, or is TLR4/LPS still dominant in real patients? The Cumpelik/Khameneh evidence is animal model + in vitro; human C5a-priming dominance remains to be confirmed in vivo. — see complement-c5a-gout.md, NLRP3 / Gout Biology §Priming above.

  2. What is the optimal EPA:DHA ratio for gout-specific SPM production (RvD1/MaR1 vs. RvE1), and does this differ from the cardiovascular-optimized ratio? The 2026-04-24 pass found direct MSU gout animal-model evidence is entirely DHA-derived, contradicting the cardiovascular-biased EPA-dominant recommendation currently in supplements-stack.md. — see spm-resolution-pathway.md, validation-experiments.md §3.8, Safety / Self-Experiment §Biomarker design above.

  3. Can lactoferrin be expressed in A. oryzae at therapeutically relevant titers in solid-state rice fermentation? P. pastoris 3.5 g/L submerged and A. awamori >2 g/L submerged (Ward 1995, PMID 9634791) are both demonstrated; solid-state koji is the missing data point. (2026-04-24 literature check upgraded this from "speculative Year 5+" to "near-term Year 2-3 with a defined feasibility experiment.") — see engineered-koji-protocol.md §16, spm-resolution-pathway.md §5, Compound-specific §Lactoferrin above.

  4. Is TNFSF14/LIGHT elevation a universal feature of gout flares or a patient subtype? Would a TNFSF14 biomarker identify responders to EGCG or CERC-002 better than generic hs-CRP? — see tnfsf14-gout-target.md, NLRP3 / Gout Biology §Priming above.

  5. Does zileuton (5-LOX inhibitor) abort or shorten gout flares in any case series or retrospective data? Asthma patients who also have gout are the natural population to query for retrospective signal. — see validation-experiments.md §3.9, Compound-specific §Zileuton above.

Maintenance

  • When resolved. If a question is answered by a new experiment, paper, or synthesis pass, move the entry to a resolved footer (or delete outright and note the resolution in the relevant page's log). Don't silently drop questions — explicit resolution is part of the evidence discipline.
  • When added. New questions surfaced by wiki page edits or synthesis sweeps get added to the relevant topic section. If the question is entirely novel (no existing topic fits), add a new subsection.
  • Cross-links. Every question should point back to the wiki page(s) where it is elaborated. If a question only lives here, that's a flag — it should have a home page too.

This document is a meta-index. It doesn't try to answer questions — it tracks what we don't yet know so the next sweep / experiment / researcher has a clean view of the research frontier.