Smirnova I N, Skvortsevich E G, Boldyrev A A, Panteleeva N S
Biokhimiia. 1977 Nov;42(11):2035-8.
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.
在钠钾-ATP酶反应过程中研究了氧同位素交换（18O交换）反应。结果表明，在ATP和对硝基苯磷酸酯（p-NPP）存在的情况下，体系中发生了中间型和直接型18O交换。这些发现表明，在这两种情况下的水解过程中存在相同的中间体。中间型18O交换分别被N-乙基马来酰亚胺、羟胺和2.0--1.5个18O原子激活。哇巴因对18O交换的检测没有影响。ATP和p-NPP水解过程中的中间型18O交换水平分别等于1.3--1.4个和2.0--1.5个18O原子。在ATP和p-NPP水解的中间步骤检测到18O交换反应，这意味着钠钾-ATP酶破坏这些底物的某些阶段是相同的。
