Apell H J, Marcus M M
Biochim Biophys Acta. 1986 Nov 17;862(2):254-64. doi: 10.1016/0005-2736(86)90226-9.
(Na+ + K+)-ATPase from kidney outer medulla was incorporated into artificial dioleoylphosphatidylcholine vesicles. Transport activity was induced by adding ATP to the external medium. A voltage-sensitive dye was used to detect the ATP-driven potassium extrusion in the presence of valinomycin. The observed substrate-protein interactions of the reconstituted (Na+ + K+)-ATPase largely agree with that from native tissues. An agreement between ATP hydrolysis and transport activity is given for concentration dependences of sodium, potassium, magnesium and calcium ions. The only significant deviations were observed in the influence of pH. Protons were found to have different influence on transport, enzymatic activity and phosphorylation of the enzyme. The transport studies showed a twofold interaction of protons with the protein: competition with sodium at the cytoplasmic ion binding sites, a non competitive inhibition of transport which is not correlated with protein phosphorylation.
来自肾外髓质的（钠 + 钾）-ATP 酶被整合到人工二油酰磷脂酰胆碱囊泡中。通过向外部介质中添加 ATP 来诱导转运活性。在缬氨霉素存在的情况下，使用电压敏感染料检测 ATP 驱动的钾离子外流。重组（钠 + 钾）-ATP 酶观察到的底物 - 蛋白质相互作用在很大程度上与天然组织中的一致。给出了钠、钾、镁和钙离子浓度依赖性下 ATP 水解与转运活性之间的一致性。仅在 pH 的影响方面观察到显著偏差。发现质子对转运、酶活性和酶的磷酸化有不同影响。转运研究表明质子与蛋白质有双重相互作用：在细胞质离子结合位点与钠竞争，对转运的非竞争性抑制与蛋白质磷酸化无关。
