{"id":"ac65bbf4-6867-567e-ae29-b148f0c24d5a","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-pump-sodium-atp-coupling","predicate":"couples-atp-hydrolysis-to","statement":"Ouabain-sensitive extrusion was approximately three sodium ions per ATP hydrolyzed in resealed erythrocyte ghosts.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"aea0bd62-0c21-5438-8d60-7f165ebd4383","mechanism_event_label":"ATP consumption pays for sodium extrusion while potassium is available externally.","subject":{"id":"27c3e7bd-c6e1-5344-8130-b231a9da2cfb","slug":"sodium-potassium-atpase","display_name":"Sodium-potassium ATPase complexes","entity_type_key":"protein_family"},"object":{"id":"77f557fd-965b-58d8-a2b4-6c0102f5ea41","slug":"sodium-pump-sodium-efflux","display_name":"Sodium-pump-mediated sodium efflux","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"aea0bd62-0c21-5438-8d60-7f165ebd4383","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-pump-sodium-atp-coupling-event","event_type":"biochemical_relationship","label":"ATP consumption pays for sodium extrusion while potassium is available externally.","description":"Ouabain-sensitive extrusion was approximately three sodium ions per ATP hydrolyzed in resealed erythrocyte ghosts.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"5dd31e52-f51e-51f3-880e-240abcc0ab1d","slug":"potassium-ion","display_name":"Potassium ion","entity_type_key":"ion"},"role":"extracellular transported partner","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"38de8704-84db-5770-ac1d-242cd787e798","slug":"sodium-ion","display_name":"Sodium ion","entity_type_key":"ion"},"role":"exported substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"58b974f1-d389-5bf6-81cd-889c44442c42","slug":"atp","display_name":"ATP","entity_type_key":"small_molecule"},"role":"hydrolyzed substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"cofactor","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"27c3e7bd-c6e1-5344-8130-b231a9da2cfb","slug":"sodium-potassium-atpase","display_name":"Sodium-potassium ATPase complexes","entity_type_key":"protein_family"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"77f557fd-965b-58d8-a2b4-6c0102f5ea41","slug":"sodium-pump-sodium-efflux","display_name":"Sodium-pump-mediated sodium efflux","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Sodium export couples to potassium-supported pump cycling and magnesium-dependent energy use.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Radiotracer sodium and ATP-hydrolysis assay.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This measurement does not itself establish an exact two-potassium ratio.","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":"Human","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"ATP consumption pays for sodium extrusion while potassium is available externally.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[garrahan-1967-pump] The stoicheiometry of the sodium pump (1967). https://pmc.ncbi.nlm.nih.gov/articles/PMC1365482/ DOI: 10.1113/jphysiol.1967.sp008297","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Erythrocyte membrane","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"d1b1eaeb-5d67-5ed6-9fde-e532e887ccaa","evidence_kind":"source_excerpt","locator":"Lines 587-597","start_line":587,"end_line":597,"excerpt":"### k-pump-sodium-atp-coupling\nOuabain-sensitive extrusion was approximately three sodium ions per ATP hydrolyzed in resealed erythrocyte ghosts.\nCondition category: normal\nnutrient_topic: Potassium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: ATP consumption pays for sodium extrusion while potassium is available externally.\norganism: Human\ntissue_or_cell_type: Erythrocyte membrane\nexperimental_model: Radiotracer sodium and ATP-hydrolysis assay.\nlimitations: This measurement does not itself establish an exact two-potassium ratio.\ncross_nutrient: Sodium export couples to potassium-supported pump cycling and magnesium-dependent energy use.\n[garrahan-1967-pump] The stoicheiometry of the sodium pump (1967). https://pmc.ncbi.nlm.nih.gov/articles/PMC1365482/ DOI: 10.1113/jphysiol.1967.sp008297","model_system":"Radiotracer sodium and ATP-hydrolysis assay.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. 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