Tominaga S, Kaziro Y
J Biochem. 1983 Apr;93(4):1093-100. doi: 10.1093/oxfordjournals.jbchem.a134234.
The catalytic properties of two ATPases which had been purified from bovine brain microtubules (Tominaga, S. & Kaziro, Y. (1983) J. Biochem. 93, 1085-1092) were studied. ATPase I, which had a molecular weight of 33,000, required the presence of 1.0 microM tubulin, 0.2 mM Mg2+, and 10 mM Ca2+ for maximal activity. The activation of ATPase I by tubulin was specific to the native form of tubulin, which could not be replaced by F-actin or tubulin denatured either by heat or more mildly by dialysis in the absence of glycerol. ATPase I was not specific to ATP, and GTP, and to a lesser extent, UTP and CTP were also hydrolyzed. Km for ATP of ATPase I was about 0.04 mM. ATPase I was inhibited by 5 mM Mg2+, 0.04 M K+, 10(-3) M vanadate, 10 mM N-ethylmaleimide, or 20% (v/v) glycerol. ATPase II, which was associated with membrane vesicles, required the presence of 0.2-2.0 mM Mg2+ and 20 mM KCl for activity. Tubulin stimulated the reaction of ATPase II only partially, and the addition of Ca2+ was rather inhibitory. ATPase II was specific to ATP with a Km value of 0.14 mM. It was inhibited by 1.6 mM N-ethylmaleimide and 20% (v/v) glycerol, but was not very sensitive to vanadate. Instead, ATPase II was inhibited by trifluoperazine, chlorpromazine, and nicardipin at 10(-3) M.
对从牛脑微管中纯化得到的两种ATP酶的催化特性进行了研究（富永，S. 和和木，Y.（1983年）《生物化学杂志》93卷，1085 - 1092页）。分子量为33,000的ATP酶I，其最大活性需要1.0微摩尔微管蛋白、0.2毫摩尔镁离子和10毫摩尔钙离子的存在。微管蛋白对ATP酶I的激活作用对微管蛋白的天然形式具有特异性，热变性或在无甘油条件下轻度透析变性的F - 肌动蛋白或微管蛋白均无法替代。ATP酶I对ATP不具有特异性，GTP也能被水解，UTP和CTP在较小程度上也可被水解。ATP酶I对ATP的米氏常数约为0.04毫摩尔。ATP酶I受到5毫摩尔镁离子、0.04摩尔钾离子、10⁻³摩尔钒酸盐、10毫摩尔N - 乙基马来酰亚胺或20%（体积/体积）甘油的抑制。与膜泡相关的ATP酶II，其活性需要0.2 - 2.0毫摩尔镁离子和20毫摩尔氯化钾的存在。微管蛋白仅部分刺激ATP酶II的反应，添加钙离子反而具有抑制作用。ATP酶II对ATP具有特异性，米氏常数为0.14毫摩尔。它受到1.6毫摩尔N - 乙基马来酰亚胺和20%（体积/体积）甘油的抑制，但对钒酸盐不太敏感。相反，ATP酶II受到10⁻³摩尔三氟拉嗪、氯丙嗪和尼卡地平的抑制。
