在ATP和鬼笔环肽存在的情况下肌动蛋白丝退火

Actin filament annealing in the presence of ATP and phalloidin.

作者信息

Kinosian H J, Selden L A, Estes J E, Gershman L C

机构信息

Department of Physiology, Albany Medical College, New York 12208.

出版信息

Biochemistry. 1993 Nov 23;32(46):12353-7. doi: 10.1021/bi00097a011.

DOI:10.1021/bi00097a011

PMID:8241122

Abstract

The re-formation of actin filaments after fragmentation by sonication in the presence of phalloidin and ATP has been found to follow second-order kinetics. The data are described by a model in which the rate of actin filament annealing is proportional to the square of the number concentration of actin filaments and the rate of fragmentation is proportional to the actin polymer concentration. In the presence of 100 mM KCl, 1 mM MgCl2, and equimolar phalloidin, the second-order rate constant for annealing of actin filaments is 2.2 x 10(6) M-1 s-1 and the first-order rate constant for fragmentation is 7 x 10(-7) s-1. In addition, the observed pseudo-first-order rate constant for annealing was found to increase with increasing ionic strength. Thus, annealing may play a major part in the length redistribution phase of actin polymerization and may be important for actin filament rearrangement in the cell.

摘要

已发现，在鬼笔环肽和ATP存在的情况下，经超声破碎后的肌动蛋白丝重新形成遵循二级动力学。该数据由一个模型描述，其中肌动蛋白丝退火速率与肌动蛋白丝数量浓度的平方成正比，而破碎速率与肌动蛋白聚合物浓度成正比。在含有100 mM KCl、1 mM MgCl2和等摩尔鬼笔环肽的情况下，肌动蛋白丝退火的二级速率常数为2.2×10(6) M-1 s-1，破碎的一级速率常数为7×10(-7) s-1。此外，观察到的退火拟一级速率常数随离子强度增加而增大。因此，退火可能在肌动蛋白聚合的长度重新分布阶段起主要作用，并且可能对细胞中的肌动蛋白丝重排很重要。