{"id":"bf9e2a75-1599-5385-b8aa-849b20e7ca27","stable_key":"ae1ed35d-8ce7-5936-9067-a641374bbf79:carnosine-homocarnosine","predicate":"synthesizes","statement":"Purified human CARNS1 also synthesized homocarnosine using GABA, with lower catalytic efficiency than the beta-alanine reaction.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"086f97a6-608a-5b8c-ba72-bfe8fcf075f1","mechanism_event_label":"The same enzyme can assemble a related GABA-containing peptide.","subject":{"id":"dda068ca-005f-50f4-9001-42fe79759324","slug":"human-carns1","display_name":"Human carnosine synthase / CARNS1 (ATPGD1)","entity_type_key":"protein"},"object":{"id":"385b0db7-f05a-560f-b663-65ef167ad451","slug":"homocarnosine","display_name":"Homocarnosine / GABA-L-histidine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"086f97a6-608a-5b8c-ba72-bfe8fcf075f1","stable_key":"ae1ed35d-8ce7-5936-9067-a641374bbf79:carnosine-homocarnosine-event","event_type":"observed_relationship","label":"The same enzyme can assemble a related GABA-containing peptide.","description":"Purified human CARNS1 also synthesized homocarnosine using GABA, with lower catalytic efficiency than the beta-alanine reaction.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"dda068ca-005f-50f4-9001-42fe79759324","slug":"human-carns1","display_name":"Human carnosine synthase / CARNS1 (ATPGD1)","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"385b0db7-f05a-560f-b663-65ef167ad451","slug":"homocarnosine","display_name":"Homocarnosine / GABA-L-histidine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"d5b98fa8-0612-5a5a-aa3c-6cfd8ff88867","slug":"gaba","display_name":"Gamma-aminobutyric acid","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"44374451-3436-5136-a8ae-5dcc6d8c353b","slug":"histidine","display_name":"L-Histidine","entity_type_key":"small_molecule"},"role":"context_participant","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":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"9998eb9b-0d09-58c9-885b-a442477dec8d","slug":"carnosine","display_name":"L-Carnosine / beta-alanyl-L-histidine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human enzyme substrate comparison.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Shared synthesis does not mean the two peptides have identical functions.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Carnosine collection; isomer, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"carnosine","display_name":"L-Carnosine / beta-alanyl-L-histidine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The same enzyme can assemble a related GABA-containing peptide.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Molecular identification of carnosine synthase as ATP-grasp domain-containing protein 1 (ATPGD1). · 2010 · https://pubmed.ncbi.nlm.nih.gov/20097752/ · DOI 10.1074/jbc.M109.095505","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"cb2f39bb-4092-5397-bb54-8e87b8892026","evidence_kind":"source_excerpt","locator":"Lines 36-42","start_line":36,"end_line":42,"excerpt":"## carnosine-homocarnosine\nThe same enzyme can assemble a related GABA-containing peptide.\nPurified human CARNS1 also synthesized homocarnosine using GABA, with lower catalytic efficiency than the beta-alanine reaction.\nModel: Recombinant human enzyme substrate comparison.\nLimitations: Shared synthesis does not mean the two peptides have identical functions.\nEvidence access: Primary abstract\nMolecular identification of carnosine synthase as ATP-grasp domain-containing protein 1 (ATPGD1). · 2010 · https://pubmed.ncbi.nlm.nih.gov/20097752/ · DOI 10.1074/jbc.M109.095505","model_system":"Recombinant human enzyme substrate comparison.","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":"87dc5af2-4eb6-5980-b7e0-bf3697b1156e","stable_key":"import-ae1ed35d-8ce7-5936-9067-a641374bbf79","title":"Carnosine: synthesis, transport, carbonyl chemistry and nutrient interactions (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"469cbc38203db56bd031f9d8a2dd2bfa387713950ca30199511cd137e927aa7a","revision_id":"cc409a15-8b04-50ee-a7ff-d1bf32f686bb","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}