{"id":"cba2d149-3164-546e-8206-bead3a650aef","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-neuro-hdc-histamine","predicate":"catalyzes","statement":"Recombinant human HDC catalyzes PLP-dependent histidine decarboxylation to histamine.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"18ea767e-0461-5611-8b55-aadec1d7198e","mechanism_event_label":"Activated B6 supports histamine synthesis.","subject":{"id":"fe5ba431-d43b-5aa2-8d4b-2cce24c1121c","slug":"hdc","display_name":"Human histidine decarboxylase / HDC","entity_type_key":"protein"},"object":{"id":"847daefd-ce13-541a-b426-919975168a3d","slug":"histamine","display_name":"Histamine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"18ea767e-0461-5611-8b55-aadec1d7198e","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-neuro-hdc-histamine-event","event_type":"biochemical_relationship","label":"Activated B6 supports histamine synthesis.","description":"Recombinant human HDC catalyzes PLP-dependent histidine decarboxylation to histamine.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"fe5ba431-d43b-5aa2-8d4b-2cce24c1121c","slug":"hdc","display_name":"Human histidine decarboxylase / HDC","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"cofactor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"44374451-3436-5136-a8ae-5dcc6d8c353b","slug":"histidine","display_name":"L-Histidine","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"847daefd-ce13-541a-b426-919975168a3d","slug":"histamine","display_name":"Histamine","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Recombinant engineered human HDC; crystallography and enzyme assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Recombinant HDC enzyme-activity assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Engineered soluble HDC construct; histamine release and allergy outcomes were not tested.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-b6","display_name":"Vitamin B6","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Activated B6 supports histamine synthesis.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[komori-2012-hdc] Structural Study Reveals That Ser-354 Determines Substrate Specificity on Human Histidine Decarboxylase (2012). https://pmc.ncbi.nlm.nih.gov/articles/PMC3436558/ DOI: 10.1074/jbc.M112.381897","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified recombinant protein; no intact tissue","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"0848d149-713f-57be-a5ba-8f6ef2f258fa","evidence_kind":"source_excerpt","locator":"Lines 1047-1057","start_line":1047,"end_line":1057,"excerpt":"### b6-neuro-hdc-histamine\nRecombinant human HDC catalyzes PLP-dependent histidine decarboxylation to histamine.\nCondition category: normal\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Activated B6 supports histamine synthesis.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Recombinant engineered human HDC; crystallography and enzyme assays\nlimitations: Engineered soluble HDC construct; histamine release and allergy outcomes were not tested.\nexposure: Recombinant HDC enzyme-activity assays.\n[komori-2012-hdc] Structural Study Reveals That Ser-354 Determines Substrate Specificity on Human Histidine Decarboxylase (2012). https://pmc.ncbi.nlm.nih.gov/articles/PMC3436558/ DOI: 10.1074/jbc.M112.381897","model_system":"Recombinant engineered human HDC; crystallography and enzyme assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [komori-2012-hdc] Structural Study Reveals That Ser-354 Determines Substrate Specificity on Human Histidine Decarboxylase (2012). https://pmc.ncbi.nlm.nih.gov/articles/PMC3436558/ DOI: 10.1074/jbc.M112.381897","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"251773bb-16f5-5903-b135-db4a61d9dec4","stable_key":"import-1310afbd-6010-586e-805d-551d846da421","title":"Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"ef0019b344b2219220f801a84d0d138ff6880c1be1a59540d9034bfa4334f61e","revision_id":"cac3555f-48af-5c52-a84e-add4482c87fb","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}