{"id":"e7a911bc-6f71-5517-b227-4aad3dd9c7de","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-beta-mg-atp-speciation","predicate":"modulates-atp-inhibition-of","statement":"Adding 2 mM Mg shifted apparent total-ATP inhibition from Ki 4 to 26 micromolar in excised beta-cell patches.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"ff9947a7-20b6-5f1a-9c05-a07c55247ca4","mechanism_event_label":"Magnesium changed how the potassium channel responded to total ATP.","subject":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"object":{"id":"a4a6ce6c-ada1-5c56-8adf-d2bddf959383","slug":"beta-cell-katp-current","display_name":"Pancreatic beta-cell ATP-sensitive potassium current","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"ff9947a7-20b6-5f1a-9c05-a07c55247ca4","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-beta-mg-atp-speciation-event","event_type":"biochemical_relationship","label":"Magnesium changed how the potassium channel responded to total ATP.","description":"Adding 2 mM Mg shifted apparent total-ATP inhibition from Ki 4 to 26 micromolar in excised beta-cell patches.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"58b974f1-d389-5bf6-81cd-889c44442c42","slug":"atp","display_name":"ATP","entity_type_key":"small_molecule"},"role":"free inhibitory species","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"24904faf-f4b4-5e5a-a2e6-3549fb7a2a2e","slug":"mg-atp","display_name":"Magnesium-ATP complex","entity_type_key":"chemical_species"},"role":"complexed nucleotide","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"a4a6ce6c-ada1-5c56-8adf-d2bddf959383","slug":"beta-cell-katp-current","display_name":"Pancreatic beta-cell ATP-sensitive potassium current","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Magnesium-nucleotide chemistry modifies potassium-channel gating; no dietary magnesium effect quantified.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Inside-out rat patches; Mg-free versus 2 mM Mg.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Assay concentrations are not clinical magnesium thresholds.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Potassium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"potassium","display_name":"Potassium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Rat","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Magnesium changed how the potassium channel responded to total ATP.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ashcroft-1989-magnesium] ATP-sensitive K+ channels in rat pancreatic beta-cells: modulation by ATP and Mg2+ ions (1989). https://pmc.ncbi.nlm.nih.gov/articles/PMC1189219/ DOI: 10.1113/jphysiol.1989.sp017765","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Pancreatic beta-cell membrane","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"aba3d7b4-7e32-5908-ace1-cca489ec10b8","evidence_kind":"source_excerpt","locator":"Lines 798-808","start_line":798,"end_line":808,"excerpt":"### k-beta-mg-atp-speciation\nAdding 2 mM Mg shifted apparent total-ATP inhibition from Ki 4 to 26 micromolar in excised beta-cell patches.\nCondition category: normal\nnutrient_topic: Potassium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Magnesium changed how the potassium channel responded to total ATP.\norganism: Rat\ntissue_or_cell_type: Pancreatic beta-cell membrane\nexperimental_model: Inside-out rat patches; Mg-free versus 2 mM Mg.\nlimitations: Assay concentrations are not clinical magnesium thresholds.\ncross_nutrient: Magnesium-nucleotide chemistry modifies potassium-channel gating; no dietary magnesium effect quantified.\n[ashcroft-1989-magnesium] ATP-sensitive K+ channels in rat pancreatic beta-cells: modulation by ATP and Mg2+ ions (1989). https://pmc.ncbi.nlm.nih.gov/articles/PMC1189219/ DOI: 10.1113/jphysiol.1989.sp017765","model_system":"Inside-out rat patches; Mg-free versus 2 mM Mg.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [ashcroft-1989-magnesium] ATP-sensitive K+ channels in rat pancreatic beta-cells: modulation by ATP and Mg2+ ions (1989). https://pmc.ncbi.nlm.nih.gov/articles/PMC1189219/ DOI: 10.1113/jphysiol.1989.sp017765","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"241226ee-6b7d-5cc7-9781-e6beb8ee1982","stable_key":"import-5102beb6-9f61-500e-af10-9ac63649e0b7","title":"Potassium: cross-nutrient mechanisms and deficiency (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":"a8f89f8d84b48c0f93048dfc45f7f57a67dd9a7249968a096a14aeb03d8b7a52","revision_id":"de4ec6f4-58a1-537b-8169-97b783898df1","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}