{"id":"4508dd03-a6d4-56bf-853c-75376267b9b9","stable_key":"a9dd23c6-978a-5755-8bd8-f29bd1fe0cda:b3-pre-naprt-phosphate","predicate":"activates","statement":"Inorganic phosphate activated purified recombinant human NAPRT in the reported kinetic experiments.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"08b455e9-bcf8-56f4-bc3c-8edfa30fd542","mechanism_event_label":"Phosphate supported this isolated precursor enzyme.","subject":{"id":"b28dfc54-a5ef-5f9e-ac1f-890b68e58dc3","slug":"inorganic-phosphate","display_name":"Inorganic phosphate","entity_type_key":"chemical_species"},"object":{"id":"ee8024b9-b9e9-513f-9bcd-b3d30e1990ba","slug":"naprt","display_name":"Human nicotinate phosphoribosyltransferase / NAPRT","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"08b455e9-bcf8-56f4-bc3c-8edfa30fd542","stable_key":"a9dd23c6-978a-5755-8bd8-f29bd1fe0cda:b3-pre-naprt-phosphate-event","event_type":"biochemical_relationship","label":"Phosphate supported this isolated precursor enzyme.","description":"Inorganic phosphate activated purified recombinant human NAPRT in the reported kinetic experiments.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b28dfc54-a5ef-5f9e-ac1f-890b68e58dc3","slug":"inorganic-phosphate","display_name":"Inorganic phosphate","entity_type_key":"chemical_species"},"role":"assay activator","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"ee8024b9-b9e9-513f-9bcd-b3d30e1990ba","slug":"naprt","display_name":"Human nicotinate phosphoribosyltransferase / NAPRT","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Phosphorus-containing inorganic phosphate alters a niacin precursor enzyme in vitro; no dietary phosphate deficiency was tested.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/niacin-precursors-sources/naprt2011.abstract.txt\", \"locator\": \"Indexed primary abstract; identified exact passage\", \"start_char\": 815, \"end_char\": 876, \"file_sha256\": \"c9f4959ad65f0b0621179b3ccf00c460f7f648293bf910209ecc6e7785417deb\", \"text_sha256\": \"53af728f32d65092c92246c77801e92e521892adac900df62bf3f8206129f714\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified recombinant human NAPRT kinetic assays and site-directed mutagenesis","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Biochemical or structural assay; no dietary intervention","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Purified-enzyme evidence does not establish dietary intake requirements or clinical outcomes.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Niacin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"niacin","display_name":"Niacin (vitamin B3)","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Phosphate supported this isolated precursor enzyme.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b3-pre-naprt2011] Characterization of human nicotinate phosphoribosyltransferase: Kinetic studies, structure prediction and functional analysis by site-directed mutagenesis. (2012). https://pubmed.ncbi.nlm.nih.gov/21742010/ DOI: 10.1016/j.biochi.2011.06.033","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified recombinant protein; no intact tissue","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"4364496d-618f-5424-8a09-a9ae0ae0306c","evidence_kind":"source_excerpt","locator":"Lines 262-274","start_line":262,"end_line":274,"excerpt":"### b3-pre-naprt-phosphate\nInorganic phosphate activated purified recombinant human NAPRT in the reported kinetic experiments.\nCondition category: normal\nnutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Phosphate supported this isolated precursor enzyme.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Purified recombinant human NAPRT kinetic assays and site-directed mutagenesis\nlimitations: Purified-enzyme evidence does not establish dietary intake requirements or clinical outcomes.\nexposure: Biochemical or structural assay; no dietary intervention\ncross_nutrient: Phosphorus-containing inorganic phosphate alters a niacin precursor enzyme in vitro; no dietary phosphate deficiency was tested.\nevidence_span: {\"source_cache\": \"artifacts/niacin-precursors-sources/naprt2011.abstract.txt\", \"locator\": \"Indexed primary abstract; identified exact passage\", \"start_char\": 815, \"end_char\": 876, \"file_sha256\": \"c9f4959ad65f0b0621179b3ccf00c460f7f648293bf910209ecc6e7785417deb\", \"text_sha256\": \"53af728f32d65092c92246c77801e92e521892adac900df62bf3f8206129f714\"}\n[b3-pre-naprt2011] Characterization of human nicotinate phosphoribosyltransferase: Kinetic studies, structure prediction and functional analysis by site-directed mutagenesis. 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