Component

Human mercaptopyruvate sulfurtransferase / MPST

Context-specific entity; species, compartment and exposure are stated on each claim.

10 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

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.

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.

Recorded relationships

What it acts on

  1. Human MPST supported H2S production with thioredoxin and several low-molecular-weight acceptors, including cysteine, glutathione and dihydrolipoic acid.

    Human mercaptopyruvate sulfurtransferase / MPST → Thiol acceptors in purified human MPST assays source_derived_draftungraded
    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 evidence

  2. Human MPST transfers sulfur from 3-mercaptopyruvate to its active-site Cys248, releasing pyruvate and forming an enzyme-bound persulfide.

    Human mercaptopyruvate sulfurtransferase / MPST → 3-Mercaptopyruvate source_derived_draftungraded
    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

What acts on it

  1. Human MPST2 is a mitochondrial-targeted splice isoform of MPST, distinct from cytosolic MPST1.

    Human MPST mitochondrial isoform 2 → Human mercaptopyruvate sulfurtransferase / MPST source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary indexed abstract and figure descriptions.
    experimental_model
    Recombinant human isoform characterization and sequence organisation.
    interpretation_status
    Source-derived research curation; not independent raw-data verification.
    limitations
    An isoform relationship is identity/navigation, not a signed activation effect; it does not collapse mouse and human proteins.
    nutrient_topic
    Ergothioneine mitochondrial supplement; shared molecular requirements are not demonstrated dietary interactions. · L-Ergothioneine
    plain_language
    This is the same human enzyme family with a specific splice form.
    primary_references
    Yadav et al. Thioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. DOI 10.1074/jbc.RA120.012616; PMID 32179647; https://pubmed.ncbi.nlm.nih.gov/32179647/
    source_locator
    Abstract and Figure 1

    Ergothioneine: mitochondrial transport, MPST and sulfur-handling dependencies (2026-10-02) · lines 41–41

    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 human isoform characterization and sequence organisation. · source_derived_draft · unverified_draft

    Human MPST2 is a mitochondrial-targeted splice isoform of MPST, distinct from cytosolic MPST1.
    Complete structured claim and evidence

  2. N-acetylcysteine was a poor MPST sulfur acceptor in the reported kinetic experiments.

    N-Acetyl-L-cysteine → Human mercaptopyruvate sulfurtransferase / MPST source_derived_draftungraded
    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 evidence

  3. Thioredoxin showed substrate inhibition in human MPST assays and increased the apparent Km for 3-mercaptopyruvate relative to other acceptors.

    Thioredoxin / TXN → Human mercaptopyruvate sulfurtransferase / MPST source_derived_draftungraded
    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

  4. At 4.50 mM for 24 hours, SAC increased MPST gene expression in both MCF-7 and MDA-MB-231 cells.

    S-allyl-L-cysteine / SAC → Human mercaptopyruvate sulfurtransferase / MPST source_derived_draftungraded
    Experimental context and source evidence
    acting_entity
    s-allylcysteine
    dose
    2.24, 3.37 or 4.50 mM SAC
    duration
    2, 4, 6, 8 or 24 hours
    evidence_access
    Primary abstract
    experimental_comparison
    SAC versus untreated cell controls
    experimental_model
    MCF-7 and MDA-MB-231 breast adenocarcinoma cells
    interpretation_status
    Source-derived research curation; not independent primary verification
    limitations
    High-millimolar cell exposure; mRNA does not establish enzyme flux or net H2S production.
    nutrient_topic
    S-allylcysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · S-allyl-L-cysteine / SAC
    organism
    Homo sapiens
    plain_language
    An enzyme involved in sulfur metabolism changed expression.
    primary_references
    [38397425] S-Allyl-L-Cysteine Affects Cell Proliferation and Expression of H2S-Synthetizing Enzymes in MCF-7 and MDA-MB-231 Adenocarcinoma Cell Lines. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38397425/ · DOI 10.3390/biom14020188
    route
    Cell culture
    tissue_or_cell_type
    MCF-7 and MDA-MB-231 breast adenocarcinoma cells

    S-allylcysteine: sulfur signaling, redox responses and cross-nutrient mechanisms (2026-09-20) · lines 293–300

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · MCF-7 and MDA-MB-231 breast adenocarcinoma cells · source_derived_draft · unverified_draft

    ## s-allylcysteine-breast-mpst An enzyme involved in sulfur metabolism changed expression. At 4.50 mM for 24 hours, SAC increased MPST gene expression in both MCF-7 and MDA-MB-231 cells. Model: MCF-7 and MDA-MB-231 breast adenocarcinoma cells Limitations: High-millimolar cell exposure; mRNA does not establish enzyme flux or net H2S production. Evidence access: Primary abstract [38397425] S-Allyl-L-Cysteine Affects Cell Proliferation and Expression of H2S-Synthetizing Enzymes in MCF-7 and MDA-MB-231 Adenocarcinoma Cell Lines. · 2024 · https://pubmed.ncbi.nlm.nih.gov/38397425/ · DOI 10.3390/biom14020188 Structured context: {"organism": "Homo sapiens", "tissue_or_cell_type": "MCF-7 and MDA-MB-231 breast adenocarcinoma cells", "dose": "2.24, 3.37 or 4.50 mM SAC", "duration": "2, 4, 6, 8 or 24 hours", "route": "Cell culture", "experimental_comparison": "SAC versus untreated cell controls", "acting_entity": "s-allylcysteine", "interpretation_status": "Source-derived research curation; not independent primary verification"}
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Ergothioneine bound purified human MPST2 in ITC and NMR experiments.

    L-Ergothioneine → Human MPST mitochondrial isoform 2 source_derived_draftungraded
    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_model
    Purified recombinant human MPST mitochondrial isoform 2.
    interpretation_status
    Source-derived research curation; not independent raw-data verification.
    limitations
    Binding is measured; docking poses and proposed sulfur-acceptor chemistry are not equivalent to a measured covalent intermediate. Ambiguous OCR binding constants are omitted.
    nutrient_topic
    Ergothioneine mitochondrial supplement; shared molecular requirements are not demonstrated dietary interactions. · L-Ergothioneine
    organism
    Homo sapiens
    plain_language
    Ergothioneine has an experimentally identified enzyme target.
    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/
    protein_isoform
    MPST2 · Human MPST mitochondrial isoform 2
    source_locator
    Figure 3E; Figures S3E-S3G; Results

    Ergothioneine: mitochondrial transport, MPST and sulfur-handling dependencies (2026-10-02) · lines 49–49

    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 recombinant human MPST mitochondrial isoform 2. · source_derived_draft · unverified_draft

    Ergothioneine bound purified human MPST2 in ITC and NMR experiments.
    Complete structured claim and evidence

  2. MPST-deleted HeLa cells showed no significant respiratory increase with ergothioneine versus vehicle.

    L-Ergothioneine → Basal and maximal respiration in ergothioneine-treated human HeLa cells source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    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
    vehicle in MPST-deleted HeLa cells 500 micromolar, 72 hours · L-Ergothioneine Condition belongs to the full experimental contrast; do not separate a joint intervention.
    experimental_condition
    vehicle in MPST-deleted HeLa cells CRISPR-Cas9 deletion · Human mercaptopyruvate sulfurtransferase / MPST Condition belongs to the full experimental contrast; do not separate a joint intervention.
    experimental_contrast
    {"intervention": "ergothioneine in MPST-deleted HeLa cells", "comparator": "vehicle in MPST-deleted HeLa cells", "endpoint": "basal and maximal oxygen consumption", "effect_direction": "no_detected_change", "combination": "joint", "conditions": [{"entity_slug": "ergothioneine", "state": "500 micromolar, 72 hours"}, {"entity_slug": "mpst", "state": "CRISPR-Cas9 deletion"}]} Explicit extracted experimental comparison; source-derived draft.
    experimental_model
    CRISPR-Cas9 MPST-deleted human HeLa cells; 500 micromolar ergothioneine for 72 hours.
    interpretation_status
    Source-derived research curation; not independent raw-data verification.
    limitations
    The comparison is ergothioneine versus vehicle within knockout cells. It does not show that every protective action requires MPST, or that human dietary low intake mimics knockout.
    nutrient_topic
    Ergothioneine mitochondrial supplement; shared molecular requirements are not demonstrated dietary interactions. · L-Ergothioneine
    plain_language
    Loss of the target removed this measured response.
    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 S2E-S2F; Results
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Ergothioneine: mitochondrial transport, MPST and sulfur-handling dependencies (2026-10-02) · lines 81–81

    Original AI-assisted curation of five primary studies with publication identifiers, experimental locators and access limitations. Additive chapter supplement, not publisher full text. · supports · CRISPR-Cas9 MPST-deleted human HeLa cells; 500 micromolar ergothioneine for 72 hours. · source_derived_draft · unverified_draft

    MPST-deleted HeLa cells showed no significant respiratory increase with ergothioneine versus vehicle.
    Complete structured claim and evidence

  3. Ergothioneine increased basal and maximal respiration in wild-type human HeLa cells.

    L-Ergothioneine → Basal and maximal respiration in ergothioneine-treated human HeLa cells source_derived_draftungraded
    Experimental context and source evidence
    dose
    500 micromolar
    duration
    72 hours
    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
    vehicle in wild-type HeLa cells added · L-Ergothioneine Condition belongs to the full experimental contrast; do not separate a joint intervention.
    experimental_contrast
    {"intervention": "500 micromolar ergothioneine for 72 hours", "comparator": "vehicle in wild-type HeLa cells", "endpoint": "basal and maximal oxygen consumption", "effect_direction": "increase", "combination": "single", "conditions": [{"entity_slug": "ergothioneine", "state": "added"}]} Explicit extracted experimental comparison; source-derived draft.
    experimental_model
    Human HeLa cells; 500 micromolar ergothioneine for 72 hours, as stated unambiguously in supplementary Figure S2.
    interpretation_status
    Source-derived research curation; not independent raw-data verification.
    limitations
    Cancer-cell culture at this exposure is not a clinical supplementation result or proof of a nutritional requirement.
    nutrient_topic
    Ergothioneine mitochondrial supplement; shared molecular requirements are not demonstrated dietary interactions. · L-Ergothioneine
    organism
    Homo sapiens
    plain_language
    A human cell model showed a respiratory response.
    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 S2E, wild-type panels

    Ergothioneine: mitochondrial transport, MPST and sulfur-handling dependencies (2026-10-02) · lines 73–73

    Original AI-assisted curation of five primary studies with publication identifiers, experimental locators and access limitations. Additive chapter supplement, not publisher full text. · supports · Human HeLa cells; 500 micromolar ergothioneine for 72 hours, as stated unambiguously in supplementary Figure S2. · source_derived_draft · unverified_draft

    Ergothioneine increased basal and maximal respiration in wild-type human HeLa cells.
    Complete structured claim and evidence

  4. Ergothioneine plus 3-mercaptopyruvate supported H2S release by recombinant human MPST.

    L-Ergothioneine → Hydrogen sulfide / H2S source_derived_draftungraded
    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 evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards