{"id":"16dc4494-a919-54db-a634-53ac8bf56168","stable_key":"research:msrb1-repairs-methionine","predicate":"reduces","statement":"MSRB1 reduces protein methionine-R-sulfoxide back toward the methionine state; stereochemistry and protein context matter.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"literature_reviewed:direct_experimental","direction":"positive","is_public":true,"mechanism_event_id":"6a119d21-d29a-5ed5-bce1-88fe1828cd11","mechanism_event_label":"MSRB1 repairs one specific form of oxidized methionine in proteins.","subject":{"id":"2335bf58-7537-5f18-beb0-3952c69e8a4e","slug":"msrb1","display_name":"MSRB1","entity_type_key":"protein"},"object":{"id":"aed241bf-3ab0-5f8d-8ddc-91e055b6ff4a","slug":"protein-methionine-r-sulfoxide","display_name":"Protein-bound methionine-R-sulfoxide","entity_type_key":"chemical_species"},"evidence_count":1,"mechanism_event":{"id":"6a119d21-d29a-5ed5-bce1-88fe1828cd11","stable_key":"research:msrb1-repairs-methionine","event_type":"experimentally_scoped_interaction","label":"MSRB1 repairs one specific form of oxidized methionine in proteins.","description":"MSRB1 reduces protein methionine-R-sulfoxide back toward the methionine state; stereochemistry and protein context matter.","status":"active","compartment":null,"participants":[{"entity":{"id":"2335bf58-7537-5f18-beb0-3952c69e8a4e","slug":"msrb1","display_name":"MSRB1","entity_type_key":"protein"},"role":"catalyst","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"aed241bf-3ab0-5f8d-8ddc-91e055b6ff4a","slug":"protein-methionine-r-sulfoxide","display_name":"Protein-bound methionine-R-sulfoxide","entity_type_key":"chemical_species"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"c5448053-5edf-5d0f-8027-a69cc580e030","slug":"protein-methionine","display_name":"Protein-bound methionine","entity_type_key":"chemical_species"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Human and mouse MsrB protein characterization and localization.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This experiment-specific relationship does not establish a human dietary-deficiency threshold or supplementation benefit.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"organism","value_text":"Human and mouse proteins","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a71cffab-dee3-5fb3-84f4-998f48b86c30","evidence_kind":"curated_literature_summary","locator":"lines 1042-1051","start_line":1042,"end_line":1051,"excerpt":"## msrb1-repairs-methionine\n\nMSRB1 repairs one specific form of oxidized methionine in proteins.\n\nMSRB1 reduces protein methionine-R-sulfoxide back toward the methionine state; stereochemistry and protein context matter.\n\nExperimental model: Human and mouse MsrB protein characterization and localization.\nOrganism: Human and mouse proteins\nLimitations: This experiment-specific relationship does not establish a human dietary-deficiency threshold or supplementation benefit.\nPrimary reference: [Methionine sulfoxide reduction in mammals: characterization of methionine-R-sulfoxide reductases](https://pubmed.ncbi.nlm.nih.gov/14699060/)","model_system":"Human and mouse MsrB protein characterization and localization.","directness":"author_interpretation","verification_status":"secondary_verified","notes":"Curated summary; inspect the linked primary papers for original methods and results.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f892f13-06ea-5199-a33c-a703f35c80ae","stable_key":"selenium-research-2026-09-17","title":"Selenium: literature corrections and mechanism additions","document_type":"curated_literature_review","citation_label":"Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually","file_path":"","sha256":"0b818b10c1c7120e5caf7f4d4019d7bd025d745692e424f515d3ef903c9ab7f3","revision_id":"80984e03-5f0f-5877-8094-afef7637444e","review_status":"secondary_verified","notes":"Secondary curated summaries of primary experiments, with explicit models and limitations. Not archived primary full text."}}],"relations":[],"conflicts":[],"corrections":[],"research":{"topic":"Protein repair","plain_language":"MSRB1 repairs one specific form of oxidized methionine in proteins.","evidence_scope":"direct_experimental","papers":[{"key":"catalog-msrb1-2004","title":"Methionine sulfoxide reduction in mammals: characterization of methionine-R-sulfoxide reductases","url":"https://pubmed.ncbi.nlm.nih.gov/14699060/","doi":null,"year":2004,"model":"Human and mouse MsrB protein characterization and localization.","summary":"MSRB1 reduces the R-stereoisomer of oxidized methionine and differs from compartment-specific cysteine-containing MsrB relatives."}]}}