Kolchinskaia L I, Lishko V K, Barchenko L I
Ukr Biokhim Zh (1978). 1979 May-Jun;51(3):211-7.
The vector characteristics of the interacting Na+, K+-ATPase and ouabaine were studied in experiments on the restored ghosts of erythrocytes. It is shown that the effect of K+ on the enzyme activity is the same as in cases of using ATP and p-nitrophenylphosphate (p-NPP) as phosphorylating agents. ADP removes the p-NPP induced inhibition with ouabain. This effect is explained rather by addition of ADP to the enzyme substrate centre than by a decrease in the concentration of E1 approximately P phosphoform. Incorporation of labelled orthophosphate into p-nitrophenol (NP) in the presence of Na+, K+-ATPase preparations was not detected. It is shown that antibodies against the fraction of the brain microsomes inhibit K+-NPPases to a much less extent than Na+, K+-ATPase. The digitonin treatment does not remove (Na++ATP)-dependent increase in the K+-NPPase activity. A conclusion is drawn that the mechanisms of p-NPP hydrolysis differs from the mechanism of ATP hydrolysis.
在对红细胞修复后的血影进行的实验中，研究了相互作用的钠钾 - ATP酶和哇巴因的载体特性。结果表明，钾离子对酶活性的影响与使用ATP和对硝基苯磷酸酯（p - NPP）作为磷酸化剂时的情况相同。ADP消除了哇巴因对p - NPP诱导的抑制作用。这种效应更多地是由于ADP添加到酶的底物中心，而不是由于E1~P磷酸化形式的浓度降低。在钠钾 - ATP酶制剂存在的情况下，未检测到标记的正磷酸盐掺入对硝基苯酚（NP）中。结果表明，针对脑微粒体部分的抗体对钾 - NPP酶的抑制程度远低于对钠钾 - ATP酶的抑制程度。洋地黄皂苷处理不会消除（钠 + ATP）依赖性的钾 - NPP酶活性增加。得出的结论是，p - NPP水解的机制与ATP水解的机制不同。
