title: Disulfide of thionosine triphosphate, an ATP-analog inactivating (Na+ + K+)-ATPase.
abstract: (Na+ + K+)-activated ATPase in beef brain microsomes is inactivated by the disulfide of thionosine tri[gamma-32P]phosphate, an ATP analog. The inactivation of the enzyme, which is accompanied by an incorporation of radioactivity into the membrane protein, is abolished by ATP or dithiothreitol. Since dithiothreitol restores the activity of (Na+ + K+)-ATPase, which had previously been inactivated by this ATP analog, it is concluded that thionosine triphosphate disulfide reacts with a sulfhydryl group in the ATP binding site of (Na+ + K+)-activated ATPase.
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D000818:Animals; D001921:Brain / Q000201:enzymology / Q000648:ultrastructure; D002417:Cattle; D004220:Disulfides / Q000494:pharmacology; D007292:Inosine Nucleotides / Q000494:pharmacology*; D007700:Kinetics; D008861:Microsomes / Q000201:enzymology; D008970:Molecular Weight; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000494:pharmacology
chemical_list: D004220:Disulfides; D007292:Inosine Nucleotides; D013438:Sulfhydryl Compounds; D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases; D011188:Potassium