Kinetics of ATP hydrolysis by F1-ATPase and the effects of anion activation, removal of tightly bound nucleotides, and partial inhibition of the ATPase by covalent modification.
Kinetics of ATP hydrolysis by F1-ATPase and the effects of anion activation, removal of tightly bound nucleotides, and partial inhibition of the ATPase by covalent modification.
复制标题
F1-ATPase 水解 ATP 的动力学以及阴离子激活、紧密结合的核苷酸去除以及共价修饰对 ATPase 的部分抑制的影响。
DOI：
10.1021/bi00316a027
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发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
Hatefi,Y
中科院分区：
文献类型：
--
作者：
Wong,SY;Matsuno-Yagi,A;Hatefi,Y
Siu-Yin Wong、Akemi Matsuno-Yagi 和 Youssef Hatefi* 摘要：在 1-5000 jiM 的底物 (MgATP) 浓度范围内，纯化的牛心脏线粒体 FrATPase (MF!) 进行 ATP 水解的动力学的 Eadie-Hofstee 图（v/[S] vs. v）是曲线，表明与 [MgATP] 存在负协同作用，如最初所示Ebel & Lardy (1975)[Ebel, RE, & Lardy, H. A.(1975) J. Biol。化学。 250、191-196]。对数据进行计算机分析，以获得最少数量的直线的最佳拟合，每条直线代表不同的表观 Km 和 Kmax。嗜热细菌 PS3 的 MFi 和 TFi 的最佳拟合分别是 3 个品系。 MFi 的表观 Km 值上限约为 10-6、10" 4 和 10~ 3 M，最低 Km 线的相应表观 Fmax 值（每分钟每毫克蛋白质）在微摩尔或更小范围内，而其他两条线则在十微摩尔范围内。TFi 的结果非常相似。MFi 测定中存在活化阴离子 (10 mMKHC03)中浓度使总体增加了约 50%，并消除了高 Km，但对中和低 Km 基本没有影响，表明在相应的底物浓度范围内保留了负协同性，MgITP 作为底物的动力学数据也产生了两个 Km 值。
Siu-Yin Wong, Akemi Matsuno-Yagi, and Youssef Hatefi* abstract: Eadie-Hofstee plots (v/[S] vs. v) of the kinetics of ATP hydrolysis by purified bovine heartmitochondrial FrATPase (MF!) over a substrate (MgATP) concentration range of 1-5000 jiM were curvilinear, indicating negative cooperativity with respect to [MgATP] as originally shown by Ebel & Lardy (1975)[Ebel, RE, & Lardy, H. A.(1975) J. Biol. Chem. 250, 191-196]. The data were computer an-alyzed for the best fit of the least number of straight lines, each representing a different apparent Km and Kmax. The best fits for MFi and TFi from the thermophilic bacterium PS3 were three lines in each case. The upper limits of the apparentKm values for MFi were of the order of 10-6, 10" 4, and 10~ 3 M, and the corresponding apparent Fmax values (perminute per milligram of protein) were in the range of micromoles or less for thelowest Km line and decamicromoles for the other two. The results for TFi were very similar. The presence of an activating anion (10 mMKHC03) in the MFi assay me-dium increased the overall by about 50% and eliminated the high Km but had essentially no effect on the intermediate and low Km's, indicating retention of negative cooperativity in the corresponding substrate concentration range. Kinetic data for MgITP as substrate also yielded two Km values (in