{"id":"b7dff767-e07c-5ad7-8497-52e4fb843396","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:va-bco2-eccentric-cryptoxanthin","predicate":"converts","statement":"Recombinant murine BCO2 cleaved beta-cryptoxanthin mainly to beta-apo-10-prime-carotenal.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"0c9baef2-a990-51b0-94a8-6e88bb25511e","mechanism_event_label":"BCO2 makes an apocarotenoid intermediate rather than directly performing BCO1 central cleavage.","subject":{"id":"ff46b043-690f-568e-b141-4c543b584396","slug":"bco2","display_name":"Beta-carotene oxygenase 2 / BCO2","entity_type_key":"protein"},"object":{"id":"68d8afdd-68ab-57ce-974d-ce5124ff0028","slug":"beta-apo-10-carotenal","display_name":"Beta-apo-10'-carotenal","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"0c9baef2-a990-51b0-94a8-6e88bb25511e","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:va-bco2-eccentric-cryptoxanthin-event","event_type":"biochemical_relationship","label":"BCO2 makes an apocarotenoid intermediate rather than directly performing BCO1 central cleavage.","description":"Recombinant murine BCO2 cleaved beta-cryptoxanthin mainly to beta-apo-10-prime-carotenal.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"8287af07-4ddc-58ff-a354-5766b8fb1e93","slug":"beta-cryptoxanthin","display_name":"Beta-cryptoxanthin","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"ff46b043-690f-568e-b141-4c543b584396","slug":"bco2","display_name":"Beta-carotene oxygenase 2 / BCO2","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"68d8afdd-68ab-57ce-974d-ce5124ff0028","slug":"beta-apo-10-carotenal","display_name":"Beta-apo-10'-carotenal","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_location","value_text":"Figure 10A","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant murine BCO2 and Bco1/Bco2-knockout mice given carotenoids.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"BCO2 incubated with beta-cryptoxanthin.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Intermediate transport and whole-body human pathway contribution were not established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin A research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-a","display_name":"Vitamin A","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Mus musculus recombinant protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"outcome","value_text":"Recombinant murine BCO2 cleaved beta-cryptoxanthin mainly to beta-apo-10-prime-carotenal.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"BCO2 makes an apocarotenoid intermediate rather than directly performing BCO1 central cleavage.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[va-amengual-2013] Two Carotenoid Oxygenases Contribute to Mammalian Provitamin A Metabolism (2013). https://pmc.ncbi.nlm.nih.gov/articles/PMC3837149/ DOI: 10.1074/jbc.M113.501049","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"484c5bbc-460d-5dae-9553-c6532457615e","evidence_kind":"source_excerpt","locator":"Lines 232-244","start_line":232,"end_line":244,"excerpt":"### va-bco2-eccentric-cryptoxanthin\nRecombinant murine BCO2 cleaved beta-cryptoxanthin mainly to beta-apo-10-prime-carotenal.\nCondition category: normal\nnutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: BCO2 makes an apocarotenoid intermediate rather than directly performing BCO1 central cleavage.\norganism: Mus musculus recombinant protein\ntissue_or_cell_type: Cell-free enzyme\nexperimental_model: Recombinant murine BCO2 and Bco1/Bco2-knockout mice given carotenoids.\nlimitations: Intermediate transport and whole-body human pathway contribution were not established.\nexposure: BCO2 incubated with beta-cryptoxanthin.\noutcome: Recombinant murine BCO2 cleaved beta-cryptoxanthin mainly to beta-apo-10-prime-carotenal.\nevidence_location: Figure 10A\n[va-amengual-2013] Two Carotenoid Oxygenases Contribute to Mammalian Provitamin A Metabolism (2013). https://pmc.ncbi.nlm.nih.gov/articles/PMC3837149/ DOI: 10.1074/jbc.M113.501049","model_system":"Recombinant murine BCO2 and Bco1/Bco2-knockout mice given carotenoids.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [va-amengual-2013] Two Carotenoid Oxygenases Contribute to Mammalian Provitamin A Metabolism (2013). https://pmc.ncbi.nlm.nih.gov/articles/PMC3837149/ DOI: 10.1074/jbc.M113.501049","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"0c5474e2-be48-547b-b287-9c07a59c9ff1","stable_key":"import-dff9f743-3766-5f20-a71e-d6d2bd5bfb6f","title":"Vitamin A: forms, mechanisms, deficiency and excess (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":"b217224b262abbd77d6a0c8c9beefff9c022fae4d31e2a5273915d769b9a6546","revision_id":"61008909-871f-575c-b5e2-21542689ea3c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}