{"id":"ab0c283d-cb7b-5eee-a900-de158a2a8688","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:va-bco1-dioxygen-incorporation","predicate":"supplies-oxygen-to","statement":"Isotope tracing showed that oxygen incorporated into both BCO1-generated retinal products originated from molecular oxygen.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"db6b1a6c-9151-5124-a94f-2b7e2c3bd0ba","mechanism_event_label":"BCO1 cleavage uses oxygen gas to make the two retinal aldehydes.","subject":{"id":"899c7ab0-6f81-5b38-a6bd-fbb33d66ac8d","slug":"oxygen","display_name":"Molecular oxygen","entity_type_key":"small_molecule"},"object":{"id":"194eccf2-c7a5-52a6-a0c6-1c1f6d0f3a3e","slug":"all-trans-retinal","display_name":"All-trans-retinal","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"db6b1a6c-9151-5124-a94f-2b7e2c3bd0ba","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:va-bco1-dioxygen-incorporation-event","event_type":"biochemical_relationship","label":"BCO1 cleavage uses oxygen gas to make the two retinal aldehydes.","description":"Isotope tracing showed that oxygen incorporated into both BCO1-generated retinal products originated from molecular oxygen.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"d908f2a5-bc6d-5c6f-a692-668c79fae71b","slug":"bco1","display_name":"Beta-carotene oxygenase 1 / BCO1","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"73c24cd4-9ae8-5897-8359-fa4d9e8edecb","slug":"beta-carotene","display_name":"All-trans-beta-carotene","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"899c7ab0-6f81-5b38-a6bd-fbb33d66ac8d","slug":"oxygen","display_name":"Molecular oxygen","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"194eccf2-c7a5-52a6-a0c6-1c1f6d0f3a3e","slug":"all-trans-retinal","display_name":"All-trans-retinal","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_location","value_text":"Abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human BCO1 with isotopically labeled oxygen and water.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"18O2 versus H2-18O incubations with beta-carotene.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Reaction chemistry; no claim about clinical hypoxia or oxygen supplementation.","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":"Homo sapiens recombinant protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"outcome","value_text":"Isotope tracing showed that oxygen incorporated into both BCO1-generated retinal products originated from molecular oxygen.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"BCO1 cleavage uses oxygen gas to make the two retinal aldehydes.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[va-delasena-2014] The human enzyme that converts dietary provitamin A carotenoids to vitamin A is a dioxygenase (2014). https://pubmed.ncbi.nlm.nih.gov/24668807/ DOI: 10.1074/jbc.M114.557710","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":"d929aa88-4c92-58a7-946b-bafc44918997","evidence_kind":"source_excerpt","locator":"Lines 173-185","start_line":173,"end_line":185,"excerpt":"### va-bco1-dioxygen-incorporation\nIsotope tracing showed that oxygen incorporated into both BCO1-generated retinal products originated from molecular oxygen.\nCondition category: normal\nnutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: BCO1 cleavage uses oxygen gas to make the two retinal aldehydes.\norganism: Homo sapiens recombinant protein\ntissue_or_cell_type: Cell-free enzyme\nexperimental_model: Recombinant human BCO1 with isotopically labeled oxygen and water.\nlimitations: Reaction chemistry; no claim about clinical hypoxia or oxygen supplementation.\nexposure: 18O2 versus H2-18O incubations with beta-carotene.\noutcome: Isotope tracing showed that oxygen incorporated into both BCO1-generated retinal products originated from molecular oxygen.\nevidence_location: Abstract\n[va-delasena-2014] The human enzyme that converts dietary provitamin A carotenoids to vitamin A is a dioxygenase (2014). https://pubmed.ncbi.nlm.nih.gov/24668807/ DOI: 10.1074/jbc.M114.557710","model_system":"Recombinant human BCO1 with isotopically labeled oxygen and water.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. 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