{"id":"13748fc3-c155-5113-b0e2-f69ba480ec1a","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:mmaa-mmab-offload-cob-ii","predicate":"supports","statement":"A human MMAA/MMAB repair mixture with GTP and ATP transferred cob(II)alamin from MMUT to MMAB in anaerobic spectroscopy.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"5a64be87-1eb9-5d2f-897f-ccfeef01b4d3","mechanism_event_label":"In the purified repair assay, inactive B12 moved from MMUT back to MMAB.","subject":{"id":"39366dce-a30d-5e74-8c86-2bd8ca0bad96","slug":"mmaa","display_name":"Human MMAA GTPase","entity_type_key":"protein"},"object":{"id":"fc3739de-c33a-52a2-a9a1-21cd9a13efb3","slug":"mmut-cob-ii-alamin-offloading","display_name":"Cob(II)alamin off-loading from human MMUT","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"5a64be87-1eb9-5d2f-897f-ccfeef01b4d3","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:mmaa-mmab-offload-cob-ii-event","event_type":"biochemical_relationship","label":"In the purified repair assay, inactive B12 moved from MMUT back to MMAB.","description":"A human MMAA/MMAB repair mixture with GTP and ATP transferred cob(II)alamin from MMUT to MMAB in anaerobic spectroscopy.","status":"provisional","compartment":{"slug":"mitochondrial-matrix","display_name":"Mitochondrial matrix"},"participants":[{"entity":{"id":"8f690797-c976-5a5e-886e-dc49d1b17f5a","slug":"mmut","display_name":"Human methylmalonyl-CoA mutase / MMUT","entity_type_key":"protein"},"role":"donor-protein","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"38f7c5d6-7610-5432-accb-fc06ba7b259f","slug":"mmab","display_name":"Human ATP:cob(I)alamin adenosyltransferase / MMAB","entity_type_key":"protein"},"role":"acceptor-protein","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"fe0ad86e-a233-56c6-94ea-a188d81ce1c0","slug":"cob-ii-alamin","display_name":"Cob(II)alamin","entity_type_key":"small_molecule"},"role":"cargo","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"c8ccc03a-29cc-5127-baf5-81eeb92ac780","slug":"gtp","display_name":"Guanosine triphosphate","entity_type_key":"small_molecule"},"role":"energy-substrate","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"58b974f1-d389-5bf6-81cd-889c44442c42","slug":"atp","display_name":"ATP","entity_type_key":"small_molecule"},"role":"assay-substrate","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"39366dce-a30d-5e74-8c86-2bd8ca0bad96","slug":"mmaa","display_name":"Human MMAA GTPase","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""},{"entity":{"id":"fc3739de-c33a-52a2-a9a1-21cd9a13efb3","slug":"mmut-cob-ii-alamin-offloading","display_name":"Cob(II)alamin off-loading from human MMUT","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":6,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Full text Results; Figures 2-4; cofactor off-loading and MMUT activity Methods","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified human proteins","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Anaerobic assay; MMAB, MMAA, GTP and ATP","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Reconstituted transfer; spectroscopy reports cofactor environment, not cellular turnover.","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":"In the purified repair assay, inactive B12 moved from MMUT back to MMAB.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mascarenhas-2023-nanoassembly] Architecture of the human G-protein-methylmalonyl-CoA mutase nanoassembly for B12 delivery and repair. (2023). https://pubmed.ncbi.nlm.nih.gov/37468522/ DOI: 10.1038/s41467-023-40077-4","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified protein assay","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"d56f4ec0-9476-5561-8850-3aaa69bb47d7","evidence_kind":"source_excerpt","locator":"Lines 1131-1143","start_line":1131,"end_line":1143,"excerpt":"### mmaa-mmab-offload-cob-ii\nA human MMAA/MMAB repair mixture with GTP and ATP transferred cob(II)alamin from MMUT to MMAB in anaerobic spectroscopy.\nCondition category: normal\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: In the purified repair assay, inactive B12 moved from MMUT back to MMAB.\norganism: Homo sapiens\ntissue_or_cell_type: Purified protein assay\nexperimental_model: Purified human proteins\nlimitations: Reconstituted transfer; spectroscopy reports cofactor environment, not cellular turnover.\nexposure: Anaerobic assay; MMAB, MMAA, GTP and ATP\ncross_nutrient: false\nevidence_location: Full text Results; Figures 2-4; cofactor off-loading and MMUT activity Methods\n[mascarenhas-2023-nanoassembly] Architecture of the human G-protein-methylmalonyl-CoA mutase nanoassembly for B12 delivery and repair. (2023). https://pubmed.ncbi.nlm.nih.gov/37468522/ DOI: 10.1038/s41467-023-40077-4","model_system":"Purified human proteins","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mascarenhas-2023-nanoassembly] Architecture of the human G-protein-methylmalonyl-CoA mutase nanoassembly for B12 delivery and repair. (2023). https://pubmed.ncbi.nlm.nih.gov/37468522/ DOI: 10.1038/s41467-023-40077-4","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}