Component
3-Mercaptopyruvate
Context-specific entity; species, compartment and exposure are stated on each claim.
6 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 acts on it
Human MPST transfers sulfur from 3-mercaptopyruvate to its active-site Cys248, releasing pyruvate and forming an enzyme-bound persulfide.
Experimental context and source evidence
- evidence_access
- Primary abstract and primary figure descriptions
- experimental_model
- Purified human MPST structure and kinetics at pH 7.4.
- limitations
- The upstream cysteine transamination is pathway context; this experiment does not identify its dominant human tissue isoenzyme.
- nutrient_topic
- L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
- plain_language
- A cysteine-derived intermediate hands sulfur to an enzyme before it reaches another acceptor.
- primary_references
- Structure and kinetic analysis of H2S production by human mercaptopyruvate sulfurtransferase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23698001/ · DOI 10.1074/jbc.M113.466177
L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 452–458
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified human MPST structure and kinetics at pH 7.4. · source_derived_draft · unverified_draft
## l-cysteine-mpst-sulfur-transfer A cysteine-derived intermediate hands sulfur to an enzyme before it reaches another acceptor. Human MPST transfers sulfur from 3-mercaptopyruvate to its active-site Cys248, releasing pyruvate and forming an enzyme-bound persulfide. Model: Purified human MPST structure and kinetics at pH 7.4. Limitations: The upstream cysteine transamination is pathway context; this experiment does not identify its dominant human tissue isoenzyme. Evidence access: Primary abstract and primary figure descriptions Structure and kinetic analysis of H2S production by human mercaptopyruvate sulfurtransferase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23698001/ · DOI 10.1074/jbc.M113.466177
Complete structured claim and evidence
Where it participates (unsigned role)
Without 3-mercaptopyruvate, ergothioneine produced no detected H2S in the MPST and isolated-mitochondria assays.
Experimental context and source evidence
- evidence_access
- Publisher abstract/introduction plus the authors' article and supplementary legends reproduced in an indexed document. This is source-derived extraction, not raw-data verification. Main-text OCR corrupts some micro-unit symbols; ambiguous doses and binding constants are deliberately not transcribed.
- experimental_condition
- substrate-omission baseline controls present · L-Ergothioneine Condition belongs to the full experimental contrast; do not separate a joint intervention.
- experimental_condition
- substrate-omission baseline controls omitted · 3-Mercaptopyruvate Condition belongs to the full experimental contrast; do not separate a joint intervention.
- experimental_contrast
- {"intervention": "ergothioneine with 3-mercaptopyruvate omitted", "comparator": "substrate-omission baseline controls", "endpoint": "detectable H2S signal", "effect_direction": "no_detected_change", "combination": "joint", "conditions": [{"entity_slug": "ergothioneine", "state": "present"}, {"entity_slug": "3-mercaptopyruvate", "state": "omitted"}]} Explicit extracted experimental comparison; source-derived draft.
- experimental_model
- Recombinant MPST and isolated mitochondria; substrate-omission controls.
- interpretation_status
- Source-derived research curation; not independent raw-data verification.
- limitations
- This control is not evidence of a human 3-mercaptopyruvate deficiency threshold or a universal inability to release sulfur in other systems.
- nutrient_topic
- Ergothioneine mitochondrial supplement; shared molecular requirements are not demonstrated dietary interactions. · L-Ergothioneine
- plain_language
- Ergothioneine alone did not replace the substrate.
- primary_references
- Sprenger et al. Ergothioneine controls mitochondrial function and exercise performance via direct activation of MPST. DOI 10.1016/j.cmet.2025.01.024; PMID 39965563; https://pubmed.ncbi.nlm.nih.gov/39965563/
- source_locator
- Figures S3K-S3L; Results
Ergothioneine: mitochondrial transport, MPST and sulfur-handling dependencies (2026-10-02) · lines 65–65
Original AI-assisted curation of five primary studies with publication identifiers, experimental locators and access limitations. Additive chapter supplement, not publisher full text. · supports · Recombinant MPST and isolated mitochondria; substrate-omission controls. · source_derived_draft · unverified_draft
Without 3-mercaptopyruvate, ergothioneine produced no detected H2S in the MPST and isolated-mitochondria assays.
Complete structured claim and evidenceErgothioneine plus 3-mercaptopyruvate supported H2S release by recombinant human MPST.
Experimental context and source evidence
- assay_pH
- 11
- evidence_access
- Publisher abstract/introduction plus the authors' article and supplementary legends reproduced in an indexed document. This is source-derived extraction, not raw-data verification. Main-text OCR corrupts some micro-unit symbols; ambiguous doses and binding constants are deliberately not transcribed.
- experimental_condition
- substrate conditions without ergothioneine added · L-Ergothioneine Condition belongs to the full experimental contrast; do not separate a joint intervention.
- experimental_condition
- substrate conditions without ergothioneine present · 3-Mercaptopyruvate Condition belongs to the full experimental contrast; do not separate a joint intervention.
- experimental_contrast
- {"intervention": "ergothioneine plus 3-mercaptopyruvate", "comparator": "substrate conditions without ergothioneine", "endpoint": "AzMC H2S-associated signal", "effect_direction": "increase", "combination": "joint", "conditions": [{"entity_slug": "ergothioneine", "state": "added"}, {"entity_slug": "3-mercaptopyruvate", "state": "present"}]} Explicit extracted experimental comparison; source-derived draft.
- experimental_model
- Purified human MPST activity assay using AzMC; reported buffer pH 11.
- interpretation_status
- Source-derived research curation; not independent raw-data verification.
- limitations
- The alkaline biochemical assay does not establish the same flux at physiological pH. Product signal is not proof of a structurally identified ergothioneine persulfide.
- nutrient_topic
- Ergothioneine mitochondrial supplement; shared molecular requirements are not demonstrated dietary interactions. · L-Ergothioneine
- plain_language
- Enzyme activation still needs its sulfur substrate.
- primary_references
- Sprenger et al. Ergothioneine controls mitochondrial function and exercise performance via direct activation of MPST. DOI 10.1016/j.cmet.2025.01.024; PMID 39965563; https://pubmed.ncbi.nlm.nih.gov/39965563/
- source_locator
- Figure 3G; Figure S3K; STAR Methods, Recombinant MPST activity
Ergothioneine: mitochondrial transport, MPST and sulfur-handling dependencies (2026-10-02) · lines 57–57
Original AI-assisted curation of five primary studies with publication identifiers, experimental locators and access limitations. Additive chapter supplement, not publisher full text. · supports · Purified human MPST activity assay using AzMC; reported buffer pH 11. · source_derived_draft · unverified_draft
Ergothioneine plus 3-mercaptopyruvate supported H2S release by recombinant human MPST.
Complete structured claim and evidenceHuman MPST supported H2S production with thioredoxin and several low-molecular-weight acceptors, including cysteine, glutathione and dihydrolipoic acid.
Experimental context and source evidence
- evidence_access
- Primary abstract and primary figure descriptions
- experimental_model
- Purified human MPST kinetics; concentrations and acceptors varied.
- limitations
- Some small-thiol assays used millimolar concentrations; these are not demonstrated effects of oral cysteine or lipoic acid.
- nutrient_topic
- L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
- plain_language
- Sharing a sulfur-transfer route does not make these acceptors equally effective inside cells.
- primary_references
- Structure and kinetic analysis of H2S production by human mercaptopyruvate sulfurtransferase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23698001/ · DOI 10.1074/jbc.M113.466177
L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 460–466
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified human MPST kinetics; concentrations and acceptors varied. · source_derived_draft · unverified_draft
## l-cysteine-mpst-acceptor-choice Sharing a sulfur-transfer route does not make these acceptors equally effective inside cells. Human MPST supported H2S production with thioredoxin and several low-molecular-weight acceptors, including cysteine, glutathione and dihydrolipoic acid. Model: Purified human MPST kinetics; concentrations and acceptors varied. Limitations: Some small-thiol assays used millimolar concentrations; these are not demonstrated effects of oral cysteine or lipoic acid. Evidence access: Primary abstract and primary figure descriptions Structure and kinetic analysis of H2S production by human mercaptopyruvate sulfurtransferase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23698001/ · DOI 10.1074/jbc.M113.466177
Complete structured claim and evidenceN-acetylcysteine was a poor MPST sulfur acceptor in the reported kinetic experiments.
Experimental context and source evidence
- evidence_access
- Primary abstract
- experimental_model
- Recombinant human MPST assays.
- limitations
- This does not negate NAC metabolism to cysteine or its other mechanisms.
- nutrient_topic
- L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
- plain_language
- A cysteine precursor does not necessarily substitute for cysteine in each chemical reaction.
- primary_references
- Thioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32179647/ · DOI 10.1074/jbc.RA120.012616
L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 476–482
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human MPST assays. · source_derived_draft · unverified_draft
## l-cysteine-mpst-nac-distinction A cysteine precursor does not necessarily substitute for cysteine in each chemical reaction. N-acetylcysteine was a poor MPST sulfur acceptor in the reported kinetic experiments. Model: Recombinant human MPST assays. Limitations: This does not negate NAC metabolism to cysteine or its other mechanisms. Evidence access: Primary abstract Thioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32179647/ · DOI 10.1074/jbc.RA120.012616
Complete structured claim and evidenceThioredoxin showed substrate inhibition in human MPST assays and increased the apparent Km for 3-mercaptopyruvate relative to other acceptors.
Experimental context and source evidence
- evidence_access
- Primary abstract
- experimental_model
- Recombinant human MPST isoform kinetics.
- limitations
- Predicted tissue sulfur allocation was based on simulations; no human dietary response was measured.
- nutrient_topic
- L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Cysteine
- plain_language
- More of a redox partner did not simply produce a faster reaction.
- primary_references
- Thioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32179647/ · DOI 10.1074/jbc.RA120.012616
L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19) · lines 468–474
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human MPST isoform kinetics. · source_derived_draft · unverified_draft
## l-cysteine-mpst-thioredoxin-inhibition More of a redox partner did not simply produce a faster reaction. Thioredoxin showed substrate inhibition in human MPST assays and increased the apparent Km for 3-mercaptopyruvate relative to other acceptors. Model: Recombinant human MPST isoform kinetics. Limitations: Predicted tissue sulfur allocation was based on simulations; no human dietary response was measured. Evidence access: Primary abstract Thioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32179647/ · DOI 10.1074/jbc.RA120.012616
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.