{"id":"37a6c19c-7286-592f-83ff-728b709c929a","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-neuro-ginkgotoxin-plp-competition","predicate":"inhibits","statement":"Ginkgotoxin competed with pyridoxal and delayed PLP formation by human PDXK; increasing pyridoxal alleviated inhibition.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"a4e89dd9-0711-5f59-9a89-e8c4b6dba925","mechanism_event_label":"The toxin competes for the enzyme that activates B6.","subject":{"id":"fd3806da-7e3c-571c-9775-6cd843bcbf9b","slug":"ginkgotoxin","display_name":"Ginkgotoxin / 4-prime-O-methylpyridoxine","entity_type_key":"small_molecule"},"object":{"id":"d2d46db7-13a4-595f-adaa-70ad6ca31a6c","slug":"pdxk","display_name":"Pyridoxal kinase / PDXK","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"a4e89dd9-0711-5f59-9a89-e8c4b6dba925","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-neuro-ginkgotoxin-plp-competition-event","event_type":"biochemical_relationship","label":"The toxin competes for the enzyme that activates B6.","description":"Ginkgotoxin competed with pyridoxal and delayed PLP formation by human PDXK; increasing pyridoxal alleviated inhibition.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"fd3806da-7e3c-571c-9775-6cd843bcbf9b","slug":"ginkgotoxin","display_name":"Ginkgotoxin / 4-prime-O-methylpyridoxine","entity_type_key":"small_molecule"},"role":"competing-substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d2d46db7-13a4-595f-adaa-70ad6ca31a6c","slug":"pdxk","display_name":"Pyridoxal kinase / PDXK","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"9bf6269d-9e01-553d-bd8b-11a0d613bfca","slug":"pyridoxal","display_name":"Pyridoxal","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"experimental_model","value_text":"Purified recombinant human PDXK; HPLC and kinetic competition assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"25 micromolar pyridoxal with 12.5-25 micromolar ginkgotoxin in illustrative co-incubations.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Reported Ki was assay-specific; not a clinical exposure limit.","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":"The toxin competes for the enzyme that activates B6.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[kastner-2007-ginkgotoxin] The human pyridoxal kinase, a plausible target for ginkgotoxin from Ginkgo biloba (2007). https://doi.org/10.1111/j.1742-4658.2007.05654.x DOI: 10.1111/j.1742-4658.2007.05654.x","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},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"709a9908-9124-5c26-af45-c5599b91a059","evidence_kind":"source_excerpt","locator":"Lines 1196-1206","start_line":1196,"end_line":1206,"excerpt":"### b6-neuro-ginkgotoxin-plp-competition\nGinkgotoxin competed with pyridoxal and delayed PLP formation by human PDXK; increasing pyridoxal alleviated inhibition.\nCondition category: machinery_impairment\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The toxin competes for the enzyme that activates B6.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Purified recombinant human PDXK; HPLC and kinetic competition assays\nlimitations: Reported Ki was assay-specific; not a clinical exposure limit.\nexposure: 25 micromolar pyridoxal with 12.5-25 micromolar ginkgotoxin in illustrative co-incubations.\n[kastner-2007-ginkgotoxin] The human pyridoxal kinase, a plausible target for ginkgotoxin from Ginkgo biloba (2007). https://doi.org/10.1111/j.1742-4658.2007.05654.x DOI: 10.1111/j.1742-4658.2007.05654.x","model_system":"Purified recombinant human PDXK; HPLC and kinetic competition assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [kastner-2007-ginkgotoxin] The human pyridoxal kinase, a plausible target for ginkgotoxin from Ginkgo biloba (2007). https://doi.org/10.1111/j.1742-4658.2007.05654.x DOI: 10.1111/j.1742-4658.2007.05654.x","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}