{"id":"e48bc9e5-79bf-5cf3-9e00-c84a4229c6d9","stable_key":"9a47f338-d127-5e4d-abf6-e99056833a69:d-aspartate-ddo-substrate-activation","predicate":"activates_tested","statement":"Porcine DDO showed substrate activation above approximately 0.2 mM D-aspartate; N-methyl-D-aspartate instead produced substrate inhibition.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"b59580af-2696-5998-a55b-548293c56e36","mechanism_event_label":"Different substrates change the enzyme kinetics differently.","subject":{"id":"b3404670-6db1-517f-b9a0-27ecfaac558b","slug":"d-aspartate","display_name":"D-Aspartate","entity_type_key":"small_molecule"},"object":{"id":"99492fdd-f4b3-5466-bfff-b45e80d71cbc","slug":"porcine-ddo","display_name":"Porcine D-aspartate oxidase / DDO","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"b59580af-2696-5998-a55b-548293c56e36","stable_key":"9a47f338-d127-5e4d-abf6-e99056833a69:d-aspartate-ddo-substrate-activation-event","event_type":"observed_relationship","label":"Different substrates change the enzyme kinetics differently.","description":"Porcine DDO showed substrate activation above approximately 0.2 mM D-aspartate; N-methyl-D-aspartate instead produced substrate inhibition.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b3404670-6db1-517f-b9a0-27ecfaac558b","slug":"d-aspartate","display_name":"D-Aspartate","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"99492fdd-f4b3-5466-bfff-b45e80d71cbc","slug":"porcine-ddo","display_name":"Porcine D-aspartate oxidase / DDO","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"4405c054-31e8-5d20-8593-e37181234e3c","slug":"n-methyl-d-aspartate","display_name":"N-Methyl-D-aspartate","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"e2cd7179-f218-54e8-9ce9-7a836ae35fac","slug":"fad","display_name":"FAD","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified porcine enzyme concentration-response assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Do not extrapolate assay thresholds to dietary dosing.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"D-Aspartate collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"d-aspartate","display_name":"D-Aspartate","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Different substrates change the enzyme kinetics differently.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Functional and structural characterization of D-aspartate oxidase from porcine kidney: non-Michaelis kinetics due to substrate activation. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17234685/ · DOI 10.1093/jb/mvm041","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"96cc7bf4-7c2e-502c-a822-462f036d5640","evidence_kind":"source_excerpt","locator":"Lines 120-126","start_line":120,"end_line":126,"excerpt":"## d-aspartate-ddo-substrate-activation\nDifferent substrates change the enzyme kinetics differently.\nPorcine DDO showed substrate activation above approximately 0.2 mM D-aspartate; N-methyl-D-aspartate instead produced substrate inhibition.\nModel: Purified porcine enzyme concentration-response assays.\nLimitations: Do not extrapolate assay thresholds to dietary dosing.\nEvidence access: Primary abstract\nFunctional and structural characterization of D-aspartate oxidase from porcine kidney: non-Michaelis kinetics due to substrate activation. · 2007 · https://pubmed.ncbi.nlm.nih.gov/17234685/ · DOI 10.1093/jb/mvm041","model_system":"Purified porcine enzyme concentration-response 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":"3751103e-e256-5615-b24f-39cc76ccfb47","stable_key":"import-9a47f338-d127-5e4d-abf6-e99056833a69","title":"D-Aspartate: synthesis, clearance, neural and endocrine 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":"0a86a1008edb8a69dcc79409e76e3fd5ce59b0747be8cae8f21e43f871e76248","revision_id":"a1de4b66-263d-5452-8ed8-df853afba030","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}