Noguchi M, Inoué H, Kubo K
J Biochem. 1979 Feb;85(2):367-73. doi: 10.1093/oxfordjournals.jbchem.a132342.
Pellicles were isolated from Paramecium caudatum for a study of the properties of its insoluble ATPase [EC 3.6.1.3] activity. Pellicular ATPase was solubilized by sonication and fractionated by sucrose density gradient centrifugation. The sedimentation coefficient of the ATPase was about 9S. The ATPase required Ca2+ for maximum activation. Addition of neutral salts to the assay medium inhibited the activity. Substrate specificity for ATP was low; other nucleoside triphosphates were hydrolyzed at about the same rate as ATP; AMP, pyrophosphate, and p-nitrophenyl phosphate were not hydrolyzed. The ATPase activity of the pellicle preparation had a pH optimum at pH 6.5, and a Michaelis constant of 9 micrometer. On the other hand, the enzymatic properties of the ATPase were somewhat modified by the procedure of solubilization and fractionation. The pellicular ATPase does not resemble ciliary dynein ATPase or the soluble ATPase of Tetrahymena.
从尾草履虫中分离出表膜，用于研究其不溶性ATP酶[EC 3.6.1.3]活性的特性。通过超声处理使表膜ATP酶溶解，并通过蔗糖密度梯度离心进行分级分离。该ATP酶的沉降系数约为9S。ATP酶需要Ca2+才能实现最大程度的激活。向测定培养基中添加中性盐会抑制其活性。对ATP的底物特异性较低；其他核苷三磷酸的水解速率与ATP大致相同；AMP、焦磷酸和对硝基苯磷酸不会被水解。表膜制剂的ATP酶活性在pH 6.5时具有最佳pH值，米氏常数为9微摩尔。另一方面，溶解和分级分离的过程对ATP酶的酶学性质有一定程度的改变。表膜ATP酶与纤毛动力蛋白ATP酶或嗜热四膜虫的可溶性ATP酶不同。
