{"id":"2cda10c4-af89-538b-a44d-27163934c0f6","stable_key":"a8baf7e9-80e4-5d8c-adec-9a63e84d2f21:l-cysteine-mpst-nac-distinction","predicate":"is_poor_tested_acceptor_for","statement":"N-acetylcysteine was a poor MPST sulfur acceptor in the reported kinetic experiments.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"4f4ddcd4-aec1-569a-9d19-e157087867fe","mechanism_event_label":"A cysteine precursor does not necessarily substitute for cysteine in each chemical reaction.","subject":{"id":"b5fa7a22-e5a7-58d9-9e39-91a611aa431e","slug":"n-acetylcysteine","display_name":"N-Acetyl-L-cysteine","entity_type_key":"small_molecule"},"object":{"id":"bd69cbdf-a220-5981-b89f-c31b53f25f40","slug":"mpst","display_name":"Human mercaptopyruvate sulfurtransferase / MPST","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"4f4ddcd4-aec1-569a-9d19-e157087867fe","stable_key":"a8baf7e9-80e4-5d8c-adec-9a63e84d2f21:l-cysteine-mpst-nac-distinction-event","event_type":"observed_relationship","label":"A cysteine precursor does not necessarily substitute for cysteine in each chemical reaction.","description":"N-acetylcysteine was a poor MPST sulfur acceptor in the reported kinetic experiments.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b5fa7a22-e5a7-58d9-9e39-91a611aa431e","slug":"n-acetylcysteine","display_name":"N-Acetyl-L-cysteine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"bd69cbdf-a220-5981-b89f-c31b53f25f40","slug":"mpst","display_name":"Human mercaptopyruvate sulfurtransferase / MPST","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"ca899f13-50ad-55e5-ab99-329ae0038c74","slug":"l-cysteine","display_name":"L-Cysteine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"fd727c98-d9db-5c94-9fc3-8f7c6f8272df","slug":"3-mercaptopyruvate","display_name":"3-Mercaptopyruvate","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"b08835d2-3c24-52dd-b9b9-a1d34c28b14f","slug":"human-mpst-enzyme-persulfide","display_name":"Human MPST active-site cysteine persulfide","entity_type_key":"cellular_process"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human MPST assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This does not negate NAC metabolism to cysteine or its other mechanisms.","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":"A cysteine precursor does not necessarily substitute for cysteine in each chemical reaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Thioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32179647/ · DOI 10.1074/jbc.RA120.012616","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"47531499-dd2f-55b8-84bd-d458ddd5c887","evidence_kind":"source_excerpt","locator":"Lines 476-482","start_line":476,"end_line":482,"excerpt":"## l-cysteine-mpst-nac-distinction\nA cysteine precursor does not necessarily substitute for cysteine in each chemical reaction.\nN-acetylcysteine was a poor MPST sulfur acceptor in the reported kinetic experiments.\nModel: Recombinant human MPST assays.\nLimitations: This does not negate NAC metabolism to cysteine or its other mechanisms.\nEvidence access: Primary abstract\nThioredoxin regulates human mercaptopyruvate sulfurtransferase at physiologically-relevant concentrations. · 2020 · https://pubmed.ncbi.nlm.nih.gov/32179647/ · DOI 10.1074/jbc.RA120.012616","model_system":"Recombinant human MPST assays.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; 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