title: [18 O-exchange during ATP and n-nitrophenylphosphate hydrolysis by Na, K-ATPase from bovine brain].
abstract: The reaction of the oxygen isotope exchange (18O-exchange) was studied in the course of the Na, K-ATPase reaction. It was shown that the intermediary and direct 18O-exchanges occurred in the system in the presence of both ATP and p-NPP. These findings are indicative of the same intermediate during the hydrolytic process in both cases. The intermediary 18O-exchange was activated by N-ethylmaleimide, hydroxylamine and 2.0--1.5 18O atoms, respectively. The detection of 18O-exchange Ouabain had no effect on the exchange. The levels of intermediary 18O-exchange during ATP and p-NPP hydrolyses were equal to 1.3--1.4 and 2.0--1.5 18O atoms, respectively. The detection of 18O-exchange reactions at the intermediary steps of both ATP and p-NPP hydrolyses implies the identity of certain stages in the destruction of these substrates by Na, K-ATPase.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D009596:Nitrophenols / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D010101:Oxygen Consumption; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D009596:Nitrophenols; D009943:Organophosphorus Compounds; C008644:nitrophenylphosphate; D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases; D011188:Potassium
vernacular_title: 18- 180-obmen v khode gidroliza ATP i n-nitrofenilfosfata Na, K-ATPazoi iz mozga byka.