KINETICS OF THE INTERACTION OF 2'(3')-O-(N-METHYLANTHRANILOYL)-ATP WITH MYOSIN SUBFRAGMENT-1 AND ACTOMYOSIN SUBFRAGMENT-1 - CHARACTERIZATION OF 2 ACTO.S1.ADP COMPLEXES
KINETICS OF THE INTERACTION OF 2'(3')-O-(N-METHYLANTHRANILOYL)-ATP WITH MYOSIN SUBFRAGMENT-1 AND ACTOMYOSIN SUBFRAGMENT-1 - CHARACTERIZATION OF 2 ACTO.S1.ADP COMPLEXES
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DOI：
10.1021/bi00216a017
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发表时间：
1991-01-15
期刊：
影响因子：
2.9
通讯作者：
GEEVES, MA
中科院分区：
文献类型：
--
作者：
WOODWARD, SKA;ECCLESTON, JF;GEEVES, MA
我们使用了ATP的荧光类似物mantATP [2 '（3'）-O-（N-甲基邻氨基苯甲酰基）-腺苷5 '-三磷酸;平冢，T.（1983）Biochim. Biophys. Acta 742，496-508]，并对mantATP和mantADP与S1和acto.S1的相互作用进行了详细的动力学研究。 我们已经证明，这些类似物的行为像ATP和ADP，分别。 此外，我们已经证明，这种类似物可以区分两种acto.S1复合物，A-M.N（连接）和A.M.N（rigor-like）状态[Geeves，M.一、古迪河美国，& Gutfreund，H.（1984）J. Muscle Res. Cell Motil. 5，351-361]。 以前，这两种状态被观察到与芘标签上的Cys 374肌动蛋白。 这种异构化现在可以监测在两个空间上不同的网站上的三元复合物，在三元复合物中的主要构象变化的指示。 此外，我们已经直接测量了ADP从A-M.N和A.M.N中解离的速率，并显示它们相差1000倍。 因此，这里给出的结果支持Geeves等人的模型，并且与A-M.N到A.M.N的转变与横桥循环的力产生事件相耦合是一致的。
We have used a fluorescent analogue of ATP, mantATP [2'(3')-O-(N-methylanthraniloyl)-adenosine 5'-triphosphate; Hiratsuka, T. (1983) Biochim. Biophys. Acta 742, 496-508], and made a detailed kinetic study of the interaction of mantATP and mantADP with S1 and acto.S1. We have shown that these analogues behave like ATP and ADP, respectively. In addition, we have demonstrated that this analogue can distinguish between two acto.S1 complexes, the A-M.N (attached) and A.M.N (rigor-like) states [Geeves, M. A., Goody, R. S., & Gutfreund, H. (1984) J. Muscle Res. Cell Motil. 5, 351-361]. Previously, these two states were observed with a pyrene label on Cys 374 of actin. This isomerization can now be monitored at two spatially distinct sites on the ternary complex, indicative of a major conformational change in the ternary complex. Also, we have measured the rate of ADP dissociation from both A-M.N and A.M.N directly and shown these to differ by a factor of 1000. Thus the results presented here support the model of Geeves et al. and are consistent with the A-M.N to A.M.N transition being coupled to the force-generating event of the crossbridge cycle.