{"id":"b589ebeb-be55-5c1f-aab1-4da904b03a3b","stable_key":"f992b796-377d-53bf-a39b-7e5d41dbe194:b5-bio-pank2-free-carnitine","predicate":"does_not_activate_in_assay","statement":"Free carnitine did not activate purified human PANK2 in the experiment shown in Fig. 4B.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"5326e110-279c-5b7d-931c-43253319b548","mechanism_event_label":"The purified enzyme did not respond directly to free carnitine.","subject":{"id":"6e34c035-9371-578f-b799-fd2a14e9e40f","slug":"l-carnitine","display_name":"L-Carnitine","entity_type_key":"small_molecule"},"object":{"id":"496571a5-06f5-5aa5-b95b-aae8b6556c7f","slug":"pank2","display_name":"Human pantothenate kinase 2 / PANK2","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"5326e110-279c-5b7d-931c-43253319b548","stable_key":"f992b796-377d-53bf-a39b-7e5d41dbe194:b5-bio-pank2-free-carnitine-event","event_type":"biochemical_relationship","label":"The purified enzyme did not respond directly to free carnitine.","description":"Free carnitine did not activate purified human PANK2 in the experiment shown in Fig. 4B.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"f1c881ce-8094-5602-bb97-074377340185","slug":"palmitoylcarnitine","display_name":"Palmitoyl-L-carnitine","entity_type_key":"small_molecule"},"role":"direct_activating_comparator","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"b7ed6e4c-e560-5cee-b68f-895f21862e6f","slug":"acetyl-coa","display_name":"Acetyl-CoA","entity_type_key":"small_molecule"},"role":"feedback_inhibitor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"6e34c035-9371-578f-b799-fd2a14e9e40f","slug":"l-carnitine","display_name":"L-Carnitine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"496571a5-06f5-5aa5-b95b-aae8b6556c7f","slug":"pank2","display_name":"Human pantothenate kinase 2 / PANK2","entity_type_key":"protein"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human PANK2 in 293T-cell lysates and purified enzyme assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Primary Fig. 4B purified-enzyme assay; carnitine concentration range not extracted.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The same paper observed free-carnitine activation in lysate preparations at higher concentrations, so the purified-enzyme negative result must not be generalized to every lysate condition. Neither assay tests clinical carnitine supplementation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Pantothenic acid (vitamin B5) research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"pantothenate","display_name":"Pantothenate (vitamin B5)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The purified enzyme did not respond directly to free carnitine.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b5-bio-pank2reg] Activation of human mitochondrial pantothenate kinase 2 by palmitoylcarnitine. (2007). https://pubmed.ncbi.nlm.nih.gov/17242360/ DOI: 10.1073/pnas.0607621104","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":"ef4f18fd-3ac4-5cc2-8292-c74c31aa366c","evidence_kind":"source_excerpt","locator":"Lines 626-637","start_line":626,"end_line":637,"excerpt":"### b5-bio-pank2-free-carnitine\nFree carnitine did not activate purified human PANK2 in the experiment shown in Fig. 4B.\nCondition category: normal\nnutrient_topic: Pantothenic acid (vitamin B5) research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The purified enzyme did not respond directly to free carnitine.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Human PANK2 in 293T-cell lysates and purified enzyme assays\nlimitations: The same paper observed free-carnitine activation in lysate preparations at higher concentrations, so the purified-enzyme negative result must not be generalized to every lysate condition. Neither assay tests clinical carnitine supplementation.\nexposure: Primary Fig. 4B purified-enzyme assay; carnitine concentration range not extracted.\ncross_nutrient: true\n[b5-bio-pank2reg] Activation of human mitochondrial pantothenate kinase 2 by palmitoylcarnitine. (2007). https://pubmed.ncbi.nlm.nih.gov/17242360/ DOI: 10.1073/pnas.0607621104","model_system":"Human PANK2 in 293T-cell lysates and purified enzyme assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b5-bio-pank2reg] Activation of human mitochondrial pantothenate kinase 2 by palmitoylcarnitine. 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