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concentrations and acceptors varied.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Some small-thiol assays used millimolar concentrations; these are not demonstrated effects of oral cysteine or lipoic acid.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Cysteine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-cysteine","display_name":"L-Cysteine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Sharing a sulfur-transfer route does not make these acceptors equally effective inside cells.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"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","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"3fe848da-ffc6-5852-b180-157efbc09299","evidence_kind":"source_excerpt","locator":"Lines 460-466","start_line":460,"end_line":466,"excerpt":"## l-cysteine-mpst-acceptor-choice\nSharing a sulfur-transfer route does not make these acceptors equally effective inside cells.\nHuman MPST supported H2S production with thioredoxin and several low-molecular-weight acceptors, including cysteine, glutathione and dihydrolipoic acid.\nModel: Purified human MPST kinetics; concentrations and acceptors varied.\nLimitations: Some small-thiol assays used millimolar concentrations; these are not demonstrated effects of oral cysteine or lipoic acid.\nEvidence access: Primary abstract and primary figure descriptions\nStructure and kinetic analysis of H2S production by human mercaptopyruvate sulfurtransferase. · 2013 · https://pubmed.ncbi.nlm.nih.gov/23698001/ · DOI 10.1074/jbc.M113.466177","model_system":"Purified human MPST kinetics; concentrations and acceptors varied.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"654560f6-8d7f-596b-8722-48d94053cfe3","stable_key":"import-a8baf7e9-80e4-5d8c-adec-9a63e84d2f21","title":"L-Cysteine: sulfur allocation, redox supply and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. 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