Noël F, Soares de Moura R
Exp Parasitol. 1986 Oct;62(2):298-307. doi: 10.1016/0014-4894(86)90035-4.
The preparation and some biochemical properties of a (Na+ + K+)ATPase from male adult Schistosoma mansoni are described. After incubation in a membrane disruption medium, the tegument and carcass of the worms were separated and treated to obtain fractions enriched in (Na+ + K+)ATPase. The activity of the tegumental ouabain sensitive (Na+ + K+)ATPase at 37 C was 20.3 mumole Pi X mg-1 protein X hr-1 and represented 32% of the total ATPase activity. The (Na+ + K+)ATPase prepared from the carcass had a lower specific activity (3.7 mumole Pi X mg-1 protein X hr-1) but a higher relative activity (55%). Similar concentrations of Na+ and K+ activated the enzymes from both sources, and both enzymes were inhibited by similar concentrations of calcium. However, the enzyme from carcass was ten times more sensitive to ouabain than the enzyme from tegument. Comparison with results obtained on the (Na+ + K+)ATPase of human heart showed that the enzymes from the worms were more resistant to ouabain. The half maximal inhibitory concentration of dihydroouabain compared to that of ouabain was also different in the enzymes from human and worm. We conclude that (1) there exists at least one structural difference between the (Na+ + K+)ATPase of S. mansoni and that of the human host, and (2) it is useful to separately study the enzymes from tegument and carcass because they differ in sensitivity to cardiac glycosides.
本文描述了来自成年雄性曼氏血吸虫的一种（Na⁺ + K⁺）ATP酶的制备方法及其一些生化特性。在膜破坏介质中孵育后，将虫体的皮层和虫体分离并进行处理，以获得富含（Na⁺ + K⁺）ATP酶的组分。皮层哇巴因敏感的（Na⁺ + K⁺）ATP酶在37℃时的活性为20.3微摩尔无机磷×毫克⁻¹蛋白质×小时⁻¹，占总ATP酶活性的32%。从虫体制备的（Na⁺ + K⁺）ATP酶比活性较低（3.7微摩尔无机磷×毫克⁻¹蛋白质×小时⁻¹），但相对活性较高（55%）。相似浓度的Na⁺和K⁺激活了来自两种来源的酶，且两种酶都受到相似浓度钙的抑制。然而，虫体来源的酶对哇巴因的敏感性是皮层来源酶的10倍。与人类心脏（Na⁺ + K⁺）ATP酶的结果比较表明，虫体来源的酶对哇巴因更具抗性。在人和虫体来源的酶中，双氢哇巴因与哇巴因相比的半数最大抑制浓度也不同。我们得出结论：（1）曼氏血吸虫的（Na⁺ + K⁺）ATP酶与人类宿主的（Na⁺ + K⁺）ATP酶至少存在一种结构差异；（2）分别研究皮层和虫体来源的酶是有用的，因为它们对强心苷的敏感性不同。
