{"id":"2e3d048b-173c-5e5a-b6fb-7521c63f9670","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-human-gsh-decyanation","predicate":"glutathione-dependently-converts","statement":"Purified human CblC/MMACHC supported GSH-dependent decyanation of cyanocobalamin to cob(II)alamin efficiently under anaerobic conditions; the human reaction was oxygen-sensitive.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"3f442f36-8648-5fd0-9a92-d99c505ef0ae","mechanism_event_label":"Glutathione could supply reducing power, but oxygen strongly affected this human-protein reaction.","subject":{"id":"70ae4c83-37b2-5bd7-931d-021cace41eef","slug":"mmachc","display_name":"Human MMACHC / cobalamin-processing protein CblC","entity_type_key":"protein"},"object":{"id":"4cb4dfbc-6cd9-5bd5-98dc-d0a8fb6cfee4","slug":"cyanocobalamin","display_name":"Cyanocobalamin","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"3f442f36-8648-5fd0-9a92-d99c505ef0ae","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-human-gsh-decyanation-event","event_type":"biochemical_relationship","label":"Glutathione could supply reducing power, but oxygen strongly affected this human-protein reaction.","description":"Purified human CblC/MMACHC supported GSH-dependent decyanation of cyanocobalamin to cob(II)alamin efficiently under anaerobic conditions; the human reaction was oxygen-sensitive.","status":"provisional","compartment":{"slug":"cytosol","display_name":"Cytosol"},"participants":[{"entity":{"id":"b44c9e27-4bbb-52d3-a022-14cddded5073","slug":"glutathione","display_name":"GSH","entity_type_key":"small_molecule"},"role":"electron donor","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"fe0ad86e-a233-56c6-94ea-a188d81ce1c0","slug":"cob-ii-alamin","display_name":"Cob(II)alamin","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"70ae4c83-37b2-5bd7-931d-021cace41eef","slug":"mmachc","display_name":"Human MMACHC / cobalamin-processing protein CblC","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"4cb4dfbc-6cd9-5bd5-98dc-d0a8fb6cfee4","slug":"cyanocobalamin","display_name":"Cyanocobalamin","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Abstract; indexed primary Results summary","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified human MMACHC; oxygen-controlled biochemical assay","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"GSH and specified B12 form under anaerobic versus aerobic conditions","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Abstract-level extraction; stronger aerobic activity of the C. elegans enzyme must not be attributed to human MMACHC.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Glutathione could supply reducing power, but oxygen strongly affected this human-protein reaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[li-2014-gsh-electron] Glutathione-dependent one-electron transfer reactions catalyzed by a B12 trafficking protein (2014). https://pubmed.ncbi.nlm.nih.gov/24742678/ DOI: 10.1074/jbc.M114.567339","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free assay","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"cd92da4a-4e7e-5017-95e2-617a84eaac61","evidence_kind":"source_excerpt","locator":"Lines 767-779","start_line":767,"end_line":779,"excerpt":"### b12-human-gsh-decyanation\nPurified human CblC/MMACHC supported GSH-dependent decyanation of cyanocobalamin to cob(II)alamin efficiently under anaerobic conditions; the human reaction was oxygen-sensitive.\nCondition category: normal\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Glutathione could supply reducing power, but oxygen strongly affected this human-protein reaction.\norganism: Homo sapiens\ntissue_or_cell_type: Cell-free assay\nexperimental_model: Purified human MMACHC; oxygen-controlled biochemical assay\nlimitations: Abstract-level extraction; stronger aerobic activity of the C. elegans enzyme must not be attributed to human MMACHC.\nexposure: GSH and specified B12 form under anaerobic versus aerobic conditions\ncross_nutrient: true\nevidence_location: Abstract; indexed primary Results summary\n[li-2014-gsh-electron] Glutathione-dependent one-electron transfer reactions catalyzed by a B12 trafficking protein (2014). https://pubmed.ncbi.nlm.nih.gov/24742678/ DOI: 10.1074/jbc.M114.567339","model_system":"Purified human MMACHC; oxygen-controlled biochemical assay","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [li-2014-gsh-electron] Glutathione-dependent one-electron transfer reactions catalyzed by a B12 trafficking protein (2014). https://pubmed.ncbi.nlm.nih.gov/24742678/ DOI: 10.1074/jbc.M114.567339","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"73145023-2982-5848-aff2-8d8875d6b9c5","stable_key":"import-7fc92b9e-9cbf-556e-8719-6b5244625250","title":"Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"ad5b3a51d36e856aa7fdfd1cc23f690b094689bad87d28e1a621a54675a01c92","revision_id":"118bd616-0c13-549f-bfeb-bc439715b89c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}