{"id":"dee96797-51b0-58d7-aa68-6955aaf068e5","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:cyp27b1-produces-calcitriol","predicate":"produces","statement":"Recombinant human CYP27B1 converts calcifediol to calcitriol by 1-alpha-hydroxylation in reconstituted enzyme systems.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"87b7667f-1bc7-5a4d-a225-81f81dc08d2b","mechanism_event_label":"CYP27B1 activates the vitamin D precursor.","subject":{"id":"a1d0238c-7529-5175-b5f9-71dc9bc61ed5","slug":"cyp27b1","display_name":"Vitamin D 1-alpha-hydroxylase / CYP27B1","entity_type_key":"protein"},"object":{"id":"f5156c24-108f-5746-b114-ed764e79a3f4","slug":"calcitriol","display_name":"Calcitriol","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"87b7667f-1bc7-5a4d-a225-81f81dc08d2b","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:cyp27b1-produces-calcitriol-event","event_type":"biochemical_reaction","label":"CYP27B1 activates the vitamin D precursor.","description":"Recombinant human CYP27B1 converts calcifediol to calcitriol by 1-alpha-hydroxylation in reconstituted enzyme systems.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"a1d0238c-7529-5175-b5f9-71dc9bc61ed5","slug":"cyp27b1","display_name":"Vitamin D 1-alpha-hydroxylase / CYP27B1","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"6bd73bd2-1f0a-5caa-ba69-7ce1b75364bb","slug":"calcifediol","display_name":"Calcifediol / 25-hydroxyvitamin D3","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"f5156c24-108f-5746-b114-ed764e79a3f4","slug":"calcitriol","display_name":"Calcitriol","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Recombinant human CYP27B1 expressed in bacteria and reconstituted with phospholipids and electron-transfer partners","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Activity requires electron-transfer support; this assay does not measure endocrine flux in an intact kidney.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Calcium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens enzyme","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"CYP27B1 activates the vitamin D precursor.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[tang2012cyp27b1] Expression of human CYP27B1 in Escherichia coli and characterization in phospholipid vesicles (2012). https://febs.onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2012.08736.x DOI: 10.1111/j.1742-4658.2012.08736.x","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"research_relationship_category","value_text":"biochemical_reaction","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Reconstituted membrane system","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"transport_or_reaction_direction","value_text":"forward","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"939953f6-ae1c-5f12-ae93-d143feced528","evidence_kind":"source_excerpt","locator":"Lines 349-360","start_line":349,"end_line":360,"excerpt":"### cyp27b1-produces-calcitriol\nRecombinant human CYP27B1 converts calcifediol to calcitriol by 1-alpha-hydroxylation in reconstituted enzyme systems.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: CYP27B1 activates the vitamin D precursor.\norganism: Homo sapiens enzyme\ntissue_or_cell_type: Reconstituted membrane system\nexperimental_model: Recombinant human CYP27B1 expressed in bacteria and reconstituted with phospholipids and electron-transfer partners\nlimitations: Activity requires electron-transfer support; this assay does not measure endocrine flux in an intact kidney.\nresearch_relationship_category: biochemical_reaction\ntransport_or_reaction_direction: forward\n[tang2012cyp27b1] Expression of human CYP27B1 in Escherichia coli and characterization in phospholipid vesicles (2012). https://febs.onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2012.08736.x DOI: 10.1111/j.1742-4658.2012.08736.x","model_system":"Recombinant human CYP27B1 expressed in bacteria and reconstituted with phospholipids and electron-transfer partners","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [tang2012cyp27b1] Expression of human CYP27B1 in Escherichia coli and characterization in phospholipid vesicles (2012). https://febs.onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2012.08736.x DOI: 10.1111/j.1742-4658.2012.08736.x","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3c083fa0-59c6-50e9-af42-678d0e3c1006","stable_key":"import-434e1e27-eb90-583a-956b-62472726ffba","title":"Calcium: mechanism-first literature curation (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":"965c934d6b147f2b62f8d45ce6d7a87681a600bfe5c46a585b4704889afd3fc1","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}