{"id":"5e29a136-98f8-5cce-a313-2371003d058c","stable_key":"584c58f5-ab9f-53f3-97a9-55783db943b0:tryptophan-acmsd-zinc","predicate":"requires_bound_cofactor","statement":"Recombinant human ACMSD activity increased with incorporated zinc; adding free metal to purified enzyme did not restore or increase activity.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"d65d438b-a9ca-546b-8445-52d4cfb5c34e","mechanism_event_label":"The enzyme needs properly incorporated zinc, not simply zinc added later.","subject":{"id":"ee9dbaa7-c987-5a0c-bea1-45a0c926187c","slug":"acmsd","display_name":"Human ACMS decarboxylase / ACMSD","entity_type_key":"protein"},"object":{"id":"49c806c2-7041-5020-8b3b-fa04ffa122ac","slug":"zinc-ion","display_name":"Zinc(II) ion","entity_type_key":"ion"},"evidence_count":1,"mechanism_event":{"id":"d65d438b-a9ca-546b-8445-52d4cfb5c34e","stable_key":"584c58f5-ab9f-53f3-97a9-55783db943b0:tryptophan-acmsd-zinc-event","event_type":"observed_relationship","label":"The enzyme needs properly incorporated zinc, not simply zinc added later.","description":"Recombinant human ACMSD activity increased with incorporated zinc; adding free metal to purified enzyme did not restore or increase activity.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"ee9dbaa7-c987-5a0c-bea1-45a0c926187c","slug":"acmsd","display_name":"Human ACMS decarboxylase / ACMSD","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"49c806c2-7041-5020-8b3b-fa04ffa122ac","slug":"zinc-ion","display_name":"Zinc(II) ion","entity_type_key":"ion"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"769339cb-213b-559e-acc0-07ed00368b94","slug":"l-tryptophan","display_name":"L-Tryptophan","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"f15dac08-9a7c-5aee-9208-ef2a09f02ff6","slug":"acms","display_name":"2-Amino-3-carboxymuconate-6-semialdehyde / ACMS","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, metal incorporation and kinetics","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human enzyme expression, metal analysis, kinetics and crystallography.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Copper-substituted protein was used for spectroscopy; this does not make copper its preferred physiological cofactor.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tryptophan","display_name":"L-Tryptophan","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The enzyme needs properly incorporated zinc, not simply zinc added later.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Human α-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD): a structural and mechanistic unveiling. · 2015 · https://pubmed.ncbi.nlm.nih.gov/25392945/ · DOI 10.1002/prot.24722","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"88ff6342-7a79-5a6d-bee9-1620ad8f183a","evidence_kind":"source_excerpt","locator":"Lines 218-224","start_line":218,"end_line":224,"excerpt":"## tryptophan-acmsd-zinc\nThe enzyme needs properly incorporated zinc, not simply zinc added later.\nRecombinant human ACMSD activity increased with incorporated zinc; adding free metal to purified enzyme did not restore or increase activity.\nModel: Human enzyme expression, metal analysis, kinetics and crystallography.\nLimitations: Copper-substituted protein was used for spectroscopy; this does not make copper its preferred physiological cofactor.\nEvidence access: Primary full text, metal incorporation and kinetics\nHuman α-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD): a structural and mechanistic unveiling. · 2015 · https://pubmed.ncbi.nlm.nih.gov/25392945/ · DOI 10.1002/prot.24722","model_system":"Human enzyme expression, metal analysis, kinetics and crystallography.","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":"73f9d3e7-fdc9-5418-8f3c-f4ef145f6efa","stable_key":"import-584c58f5-ab9f-53f3-97a9-55783db943b0","title":"Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (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":"7dfd20063b91900cb5c6ad675e3e675b7e25ef0fb8304eabac6f263cc5518284","revision_id":"bfafd789-fdf5-521f-bd28-c662e01ec1ea","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}