Cornelius F, Logvinenko N
Department of Biophysics, University of Aarhus, Denmark.
FEBS Lett. 1996 Feb 19;380(3):277-80. doi: 10.1016/0014-5793(96)00032-4.
Reconstituted Na+,K+-ATPase from either pig kidney or shark rectal glands was phosphorylated by cAMP dependent protein kinase, PKA. The stoichiometry was approximately 0.9 mol P(i)/mol alpha-subunit in the pig kidney enzyme and approximately 0.2 mol P(i)/mol alpha-subunit in the shark enzyme. In shark, Na+,K+-ATPase PKA phosphorylation increased the maximum hydrolytic activity for cytoplasmic Na+ activation and extracellular K+ activation without affecting the apparent K(m) values. In contrast, no significant functional effect after PKA phosphorylation was observed in pig kidney Na+,K+-ATPase.
来自猪肾或鲨鱼直肠腺的重组钠钾ATP酶可被环磷酸腺苷依赖性蛋白激酶（PKA）磷酸化。猪肾酶的化学计量约为每摩尔α亚基0.9摩尔无机磷（Pi），鲨鱼酶的化学计量约为每摩尔α亚基0.2摩尔Pi。在鲨鱼中，钠钾ATP酶的PKA磷酸化增加了细胞质钠激活和细胞外钾激活的最大水解活性，而不影响表观米氏常数（Km）值。相比之下，在猪肾钠钾ATP酶中未观察到PKA磷酸化后的显著功能效应。
