{"id":"a17513f0-818c-5088-a55e-657a2d14505e","stable_key":"09b23d0d-35e2-51ff-b1aa-b4f9227e4fa2:isoleucine-tiglyl-hydration","predicate":"hydrates","statement":"Human fibroblast and liver assays measured tiglyl-CoA hydration in the isoleucine branch; residual activity persisted despite ECHS1 deficiency, indicating overlapping hydratase capacity.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"9fbaa52c-d92c-5589-bed2-49f7fe9a1a79","mechanism_event_label":"A reaction can have backup enzyme capacity in a tissue.","subject":{"id":"23e1797b-7992-5004-85c8-2a1ada4bf806","slug":"echs1","display_name":"Short-chain enoyl-CoA hydratase / ECHS1","entity_type_key":"protein"},"object":{"id":"c63a2ebb-71ce-5926-b959-ec47493a0166","slug":"tiglyl-coa","display_name":"Tiglyl-CoA","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"9fbaa52c-d92c-5589-bed2-49f7fe9a1a79","stable_key":"09b23d0d-35e2-51ff-b1aa-b4f9227e4fa2:isoleucine-tiglyl-hydration-event","event_type":"observed_relationship","label":"A reaction can have backup enzyme capacity in a tissue.","description":"Human fibroblast and liver assays measured tiglyl-CoA hydration in the isoleucine branch; residual activity persisted despite ECHS1 deficiency, indicating overlapping hydratase capacity.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"23e1797b-7992-5004-85c8-2a1ada4bf806","slug":"echs1","display_name":"Short-chain enoyl-CoA hydratase / ECHS1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"c63a2ebb-71ce-5926-b959-ec47493a0166","slug":"tiglyl-coa","display_name":"Tiglyl-CoA","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"c85b327e-f132-5d9a-8e4b-c2976fcc0373","slug":"isoleucine","display_name":"L-Isoleucine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"38260a32-90f3-553d-b3cf-0b5392a5d649","slug":"2-methyl-3-hydroxybutyryl-coa","display_name":"2-Methyl-3-hydroxybutyryl-CoA","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary full text","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human ECHS1-deficient fibroblasts and liver; substrate-selective enzyme assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"ECHS1 activity does not establish that it is the sole required isoleucine hydratase.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Isoleucine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"isoleucine","display_name":"L-Isoleucine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A reaction can have backup enzyme capacity in a tissue.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Clinical and biochemical characterization of four patients with mutations in ECHS1. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26081110/ · DOI 10.1186/s13023-015-0290-1","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"86c20528-6eed-5fe2-83ff-4ef788109eb4","evidence_kind":"source_excerpt","locator":"Lines 194-200","start_line":194,"end_line":200,"excerpt":"## isoleucine-tiglyl-hydration\nA reaction can have backup enzyme capacity in a tissue.\nHuman fibroblast and liver assays measured tiglyl-CoA hydration in the isoleucine branch; residual activity persisted despite ECHS1 deficiency, indicating overlapping hydratase capacity.\nModel: Human ECHS1-deficient fibroblasts and liver; substrate-selective enzyme assays.\nLimitations: ECHS1 activity does not establish that it is the sole required isoleucine hydratase.\nEvidence access: Primary full text\nClinical and biochemical characterization of four patients with mutations in ECHS1. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26081110/ · DOI 10.1186/s13023-015-0290-1","model_system":"Human ECHS1-deficient fibroblasts and liver; substrate-selective enzyme assays.","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":"4b00f118-00fd-5cef-be97-13125eb958e9","stable_key":"import-09b23d0d-35e2-51ff-b1aa-b4f9227e4fa2","title":"L-Isoleucine: transport, translation, catabolism 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":"2058ff0da379586994e7fda6ae0086c60fa3173542bfaf1fb3871ad3e09f9c6c","revision_id":"f32192d4-9913-5d35-acbc-cf90ff17995e","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}