{"id":"477fc078-267a-512b-acc7-e8c0276beada","stable_key":"dc8975b1-95ff-5d9b-be17-a1c04610cca7:mo-xor-oxygen","predicate":"reduces_oxygen_to_reactive_species","statement":"In its oxidase activity, XOR can generate superoxide and hydrogen peroxide rather than exclusively transferring electrons to NAD+.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"21a663a9-7102-5d4e-9a6a-f51acc30fe4a","mechanism_event_label":"The enzyme can generate oxidants as well as carry out purine breakdown.","subject":{"id":"8de34d8a-46dc-512c-a82f-d169747b496e","slug":"xdh","display_name":"Human xanthine oxidoreductase / XDH","entity_type_key":"protein"},"object":{"id":"011511ed-2be5-566d-bd1b-9d580dab1e9c","slug":"superoxide-anion","display_name":"Superoxide radical anion","entity_type_key":"ion"},"evidence_count":1,"mechanism_event":{"id":"21a663a9-7102-5d4e-9a6a-f51acc30fe4a","stable_key":"dc8975b1-95ff-5d9b-be17-a1c04610cca7:mo-xor-oxygen-event","event_type":"biochemical_relationship","label":"The enzyme can generate oxidants as well as carry out purine breakdown.","description":"In its oxidase activity, XOR can generate superoxide and hydrogen peroxide rather than exclusively transferring electrons to NAD+.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"899c7ab0-6f81-5b38-a6bd-fbb33d66ac8d","slug":"oxygen","display_name":"Molecular oxygen","entity_type_key":"small_molecule"},"role":"acceptor","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"da9d64bc-69d4-5d97-90a4-8f0ed03e0ac8","slug":"hydrogen-peroxide","display_name":"Hydrogen peroxide","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"e2cd7179-f218-54e8-9ce9-7a836ae35fac","slug":"fad","display_name":"FAD","entity_type_key":"small_molecule"},"role":"electron transfer cofactor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"8de34d8a-46dc-512c-a82f-d169747b496e","slug":"xdh","display_name":"Human xanthine oxidoreductase / XDH","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"011511ed-2be5-566d-bd1b-9d580dab1e9c","slug":"superoxide-anion","display_name":"Superoxide radical anion","entity_type_key":"ion"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/molybdenum-research/37713777.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"30e93ea24784120403bef1dfe72cf46411f1af88946b9cc1cba3d4c45a367bf9\", \"start_char\": 0, \"end_char\": 1655, \"text_sha256\": \"30e93ea24784120403bef1dfe72cf46411f1af88946b9cc1cba3d4c45a367bf9\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant human XDH variants with urate, superoxide and NO assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Xanthine, oxygen and inorganic nitrite assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The 2023 Fig. 6E corrigendum corrects a displayed panel; authors state data and conclusions are unchanged. Enzyme activity is not a clinical benefit or dietary response.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Molybdenum research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"molybdenum","display_name":"Molybdenum","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The enzyme can generate oxidants as well as carry out purine breakdown.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mo-p37713777] Natural mutations of human XDH promote the nitrite (NO2-)-reductase capacity of xanthine oxidoreductase: A novel mechanism to promote redox health? (2023). https://pubmed.ncbi.nlm.nih.gov/37713777/ DOI: 10.1016/j.redox.2023.102864","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified human enzyme","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"47a58108-629e-576a-9b9a-326e46e502a5","evidence_kind":"source_excerpt","locator":"Lines 781-792","start_line":781,"end_line":792,"excerpt":"### mo-xor-oxygen\nIn its oxidase activity, XOR can generate superoxide and hydrogen peroxide rather than exclusively transferring electrons to NAD+.\nCondition category: normal\nnutrient_topic: Molybdenum research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The enzyme can generate oxidants as well as carry out purine breakdown.\norganism: Homo sapiens protein\ntissue_or_cell_type: Purified human enzyme\nexperimental_model: Recombinant human XDH variants with urate, superoxide and NO assays\nlimitations: The 2023 Fig. 6E corrigendum corrects a displayed panel; authors state data and conclusions are unchanged. Enzyme activity is not a clinical benefit or dietary response.\nexposure: Xanthine, oxygen and inorganic nitrite assays\nevidence_span: {\"source_cache\": \"artifacts/molybdenum-research/37713777.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"30e93ea24784120403bef1dfe72cf46411f1af88946b9cc1cba3d4c45a367bf9\", \"start_char\": 0, \"end_char\": 1655, \"text_sha256\": \"30e93ea24784120403bef1dfe72cf46411f1af88946b9cc1cba3d4c45a367bf9\"}\n[mo-p37713777] Natural mutations of human XDH promote the nitrite (NO2-)-reductase capacity of xanthine oxidoreductase: A novel mechanism to promote redox health? (2023). https://pubmed.ncbi.nlm.nih.gov/37713777/ DOI: 10.1016/j.redox.2023.102864","model_system":"Recombinant human XDH variants with urate, superoxide and NO assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mo-p37713777] Natural mutations of human XDH promote the nitrite (NO2-)-reductase capacity of xanthine oxidoreductase: A novel mechanism to promote redox health? 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