{"id":"f18b292d-a994-5bbb-a3f4-027d376892cc","stable_key":"97957230-601f-5dec-8524-0812be8fadbf:l-threonine-ketoacid-oxidation","predicate":"oxidizes","statement":"Purified BCOADC oxidized 2-oxobutyrate with a reported Km of 18 micromolar; purified PDC also accepted it, whereas OGDH did not.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"45f0c599-5292-5e69-b423-50c32faff30b","mechanism_event_label":"More than one ketoacid complex can handle this carbon skeleton in vitro.","subject":{"id":"a57dc55e-a10a-5cba-9728-5f95f141a583","slug":"study-1986-purified-bcoadc","display_name":"Purified BCOADC in the 1986 ketoacid study, source species unverified","entity_type_key":"protein"},"object":{"id":"dee03e61-050d-5bde-ad0a-7f9652799ec8","slug":"alpha-ketobutyrate","display_name":"Alpha-ketobutyrate","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"45f0c599-5292-5e69-b423-50c32faff30b","stable_key":"97957230-601f-5dec-8524-0812be8fadbf:l-threonine-ketoacid-oxidation-event","event_type":"observed_relationship","label":"More than one ketoacid complex can handle this carbon skeleton in vitro.","description":"Purified BCOADC oxidized 2-oxobutyrate with a reported Km of 18 micromolar; purified PDC also accepted it, whereas OGDH did not.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"a57dc55e-a10a-5cba-9728-5f95f141a583","slug":"study-1986-purified-bcoadc","display_name":"Purified BCOADC in the 1986 ketoacid study, source species unverified","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"dee03e61-050d-5bde-ad0a-7f9652799ec8","slug":"alpha-ketobutyrate","display_name":"Alpha-ketobutyrate","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"fcef4dc2-a7b6-5812-bc33-c8af3d83f4d0","slug":"l-threonine","display_name":"L-Threonine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"e4bf229f-8ac8-5053-a724-49dc71a5dc53","slug":"study-1986-purified-pdc","display_name":"Purified pyruvate dehydrogenase complex in the 1986 study, source species unverified","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"69ac0570-94d8-59d8-85ef-7f67cf302d16","slug":"propionyl-coa","display_name":"Propionyl-CoA","entity_type_key":"small_molecule"},"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":"Purified-enzyme comparison; source species is not specified in the accessible abstract.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This is not recorded as direct human enzyme evidence or an exclusive BCKDH route. Correction record: PubMed indexes an erratum in Biochemical Journal 1987;242(3):935. The notice text was inaccessible during this curation; its specific scope and impact remain unverified. The purified-enzyme findings are retained provisionally with this flag, and the abstract does not identify the source species. https://pubmed.ncbi.nlm.nih.gov/3800905/","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Threonine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-threonine","display_name":"L-Threonine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"More than one ketoacid complex can handle this carbon skeleton in vitro.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Oxidative decarboxylation of 4-methylthio-2-oxobutyrate by branched-chain 2-oxo acid dehydrogenase complex. · 1986 · https://pubmed.ncbi.nlm.nih.gov/3800905/ · DOI 10.1042/bj2370621","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"eac44991-77dd-5b9e-861f-f18e605aa86d","evidence_kind":"source_excerpt","locator":"Lines 306-312","start_line":306,"end_line":312,"excerpt":"## l-threonine-ketoacid-oxidation\nMore than one ketoacid complex can handle this carbon skeleton in vitro.\nPurified BCOADC oxidized 2-oxobutyrate with a reported Km of 18 micromolar; purified PDC also accepted it, whereas OGDH did not.\nModel: Purified-enzyme comparison; source species is not specified in the accessible abstract.\nLimitations: This is not recorded as direct human enzyme evidence or an exclusive BCKDH route. Correction record: PubMed indexes an erratum in Biochemical Journal 1987;242(3):935. The notice text was inaccessible during this curation; its specific scope and impact remain unverified. The purified-enzyme findings are retained provisionally with this flag, and the abstract does not identify the source species. https://pubmed.ncbi.nlm.nih.gov/3800905/\nEvidence access: Primary abstract\nOxidative decarboxylation of 4-methylthio-2-oxobutyrate by branched-chain 2-oxo acid dehydrogenase complex. · 1986 · https://pubmed.ncbi.nlm.nih.gov/3800905/ · DOI 10.1042/bj2370621","model_system":"Purified-enzyme comparison; source species is not specified in the accessible abstract.","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":"35396730-235a-537e-8a05-c6ef2960c509","stable_key":"import-97957230-601f-5dec-8524-0812be8fadbf","title":"L-Threonine: translation, intestinal barrier, metabolism 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. Not publisher full text.","file_path":"","sha256":"3365aed939d9f567bd098449c7d67c7c00fb6c9ba163dcf34dc7cf6081f324fb","revision_id":"10a7b648-8dd7-5d4e-b618-c560a6e2d3c7","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}