{"id":"38a58062-df0a-56f2-b771-660636778450","stable_key":"1deb434a-3547-51a0-a038-87b1ce79ec38:vd-act-cyp24a1-25d2","predicate":"produces","statement":"Human CYP24A1 initiated 25-hydroxyvitamin D2 oxidation by hydroxylation at C24R in the vesicle-reconstituted enzyme system.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"9748eedf-fc0d-5099-9a86-d69d5e182033","mechanism_event_label":"CYP24A1 begins one breakdown route for the D2 precursor.","subject":{"id":"c0a944e7-deb8-5f9e-8428-91496098e38f","slug":"cyp24a1","display_name":"Vitamin D 24-hydroxylase / CYP24A1","entity_type_key":"protein"},"object":{"id":"e04789d4-600a-55ec-9e5f-4a76ade2295a","slug":"24r-25-dihydroxyvitamin-d2","display_name":"24R,25-Dihydroxyvitamin D2","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"9748eedf-fc0d-5099-9a86-d69d5e182033","stable_key":"1deb434a-3547-51a0-a038-87b1ce79ec38:vd-act-cyp24a1-25d2-event","event_type":"biochemical_relationship","label":"CYP24A1 begins one breakdown route for the D2 precursor.","description":"Human CYP24A1 initiated 25-hydroxyvitamin D2 oxidation by hydroxylation at C24R in the vesicle-reconstituted enzyme system.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"c0a944e7-deb8-5f9e-8428-91496098e38f","slug":"cyp24a1","display_name":"Vitamin D 24-hydroxylase / CYP24A1","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"92118f85-ffc4-5f77-bfca-4b033b001548","slug":"25-hydroxyvitamin-d2","display_name":"25-Hydroxyvitamin D2","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"e04789d4-600a-55ec-9e5f-4a76ade2295a","slug":"24r-25-dihydroxyvitamin-d2","display_name":"24R,25-Dihydroxyvitamin D2","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"false","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Primary abstract: identified C24R products and comparative initial-rate kinetics.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Partially purified human CYP24A1 product analysis","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"25(OH)D2 substrate; concentration/time not specified in retrieved primary abstract.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Additional oxidation sites and products were not all fully identified; this is one identified initial route.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient","value_text":"Vitamin D2 and D3","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-d","display_name":"Vitamin D2 and D3","entity_type_key":"chemical_species"}},{"dimension":"nutrient_topic","value_text":"Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-d","display_name":"Vitamin D2 and D3","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"CYP24A1 begins one breakdown route for the D2 precursor.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[li2023] Inactivation of vitamin D2 metabolites by human CYP24A1. (2023). https://pubmed.ncbi.nlm.nih.gov/37495192/ DOI: 10.1016/j.jsbmb.2023.106368","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"phospholipid-vesicle membrane","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"99c87563-f41f-57a5-a821-0c9abb77ad49","evidence_kind":"source_excerpt","locator":"Lines 512-525","start_line":512,"end_line":525,"excerpt":"### vd-act-cyp24a1-25d2\nHuman CYP24A1 initiated 25-hydroxyvitamin D2 oxidation by hydroxylation at C24R in the vesicle-reconstituted enzyme system.\nCondition category: normal\nnutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: CYP24A1 begins one breakdown route for the D2 precursor.\norganism: Homo sapiens protein\ntissue_or_cell_type: phospholipid-vesicle membrane\nexperimental_model: Partially purified human CYP24A1 product analysis\nlimitations: Additional oxidation sites and products were not all fully identified; this is one identified initial route.\nexposure: 25(OH)D2 substrate; concentration/time not specified in retrieved primary abstract.\ncross_nutrient: false\nevidence_location: Primary abstract: identified C24R products and comparative initial-rate kinetics.\nnutrient: Vitamin D2 and D3\n[li2023] Inactivation of vitamin D2 metabolites by human CYP24A1. 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