Component
Nattokinase Ser33Ala, Asp60Ala, Ser62Ala and Thr220Ala mutants
Four single alanine substitutions removing transition-state hydrogen bonds around the catalytic triad.
2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What it acts on
The same four substitutions left Km essentially unchanged, so the bonds support catalysis rather than ground-state substrate binding.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- duration
- Not stated here
- evidence_access
- Primary PubMed abstract and indexed metadata reviewed. Full-text method details not stated here remain unresolved.
- experimental_model
- Recombinant subtilisin NK mutants
- exposure
- Ser33Ala, Asp60Ala, Ser62Ala and Thr220Ala single mutants
- limitations
- A measured null on one model substrate. Simulation partially released Asp32, His64 and Asn155 in the mutants, which is the proposed explanation rather than a separate measurement.
- organism
- Recombinant subtilisin NK mutants
- plain_language
- The same four substitutions left Km essentially unchanged, so the bonds support catalysis rather than ground-state substrate binding.
- primary_references
- Probing the importance of hydrogen bonds in the active site of the subtilisin nattokinase by site-directed mutagenesis and molecular dynamics simulation. (2006) https://pubmed.ncbi.nlm.nih.gov/16411898/ DOI: 10.1042/BJ20050772
- route
- In vitro
- tissue
- Enzyme kinetics with molecular dynamics and free-energy perturbation
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Nattokinase: what the purified enzyme cleaves, what survives being eaten, and the gap between the two (2026-09-23) · lines 81–81
Original AI-assisted curation built from a supplied entity-first document of 105 entities and 129 claims. Every reference in that document was resolved against live PubMed with its abstract read and its DOI cross-checked on 2026-09-23, and the EFSA novel-food opinion was retrieved and read in full. That check corrected two PMIDs that pointed at unrelated papers, two DOIs, and two papers recorded as carrying no erratum that do carry one; it also reversed three findings the supplied document had stated backwards. Two papers carry a published correction, recorded as such and not as a retraction. Three sources are not indexed in PubMed and are cited by what they have. Laboratory lineages are recorded, so the four papers from one group, the three from another and the two readings of a single applicant dossier cannot be counted as separate lines of support. Study-specific doses, units, populations and limitations retained; activity units are never converted between systems. Not publisher full text. · supports · Recombinant subtilisin NK mutants · source_derived_draft · unverified_draft
The same four substitutions left Km essentially unchanged, so the bonds support catalysis rather than ground-state substrate binding.
Complete structured claim and evidenceAlanine substitution at Ser33, Asp60, Ser62 or Thr220 raised the free energy of the transition state and lowered kcat.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- duration
- Not stated here
- evidence_access
- Primary PubMed abstract and indexed metadata reviewed. Full-text method details not stated here remain unresolved.
- experimental_model
- Recombinant subtilisin NK mutants
- exposure
- Ser33Ala, Asp60Ala, Ser62Ala and Thr220Ala single mutants
- limitations
- Measured against succinyl-Ala-Ala-Pro-Phe-p-nitroanilide. The exact kinetic constants were not extracted for this ledger, and an effect size on a chromogenic model substrate does not transfer to fibrin, PAI-1 or von Willebrand factor.
- organism
- Recombinant subtilisin NK mutants
- plain_language
- Alanine substitution at Ser33, Asp60, Ser62 or Thr220 raised the free energy of the transition state and lowered kcat.
- primary_references
- Probing the importance of hydrogen bonds in the active site of the subtilisin nattokinase by site-directed mutagenesis and molecular dynamics simulation. (2006) https://pubmed.ncbi.nlm.nih.gov/16411898/ DOI: 10.1042/BJ20050772
- route
- In vitro
- tissue
- Enzyme kinetics with molecular dynamics and free-energy perturbation
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Nattokinase: what the purified enzyme cleaves, what survives being eaten, and the gap between the two (2026-09-23) · lines 70–70
Original AI-assisted curation built from a supplied entity-first document of 105 entities and 129 claims. Every reference in that document was resolved against live PubMed with its abstract read and its DOI cross-checked on 2026-09-23, and the EFSA novel-food opinion was retrieved and read in full. That check corrected two PMIDs that pointed at unrelated papers, two DOIs, and two papers recorded as carrying no erratum that do carry one; it also reversed three findings the supplied document had stated backwards. Two papers carry a published correction, recorded as such and not as a retraction. Three sources are not indexed in PubMed and are cited by what they have. Laboratory lineages are recorded, so the four papers from one group, the three from another and the two readings of a single applicant dossier cannot be counted as separate lines of support. Study-specific doses, units, populations and limitations retained; activity units are never converted between systems. Not publisher full text. · supports · Recombinant subtilisin NK mutants · source_derived_draft · unverified_draft
Alanine substitution at Ser33, Asp60, Ser62 or Thr220 raised the free energy of the transition state and lowered kcat.
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.