需要亚化学计量浓度的ATP-球状肌动蛋白来使由钙离子聚合的肌动蛋白退火。

Substoichiometric concentrations of ATP-G-actin are required to anneal actin polymerized by calcium ions.

作者信息

Grazi E, Trombetta G, Rizzieri L, Guidoboni M

机构信息

Istituto di Chimica Biologica, Università di Ferrara, Italy.

出版信息

Biochem Biophys Res Commun. 1989 Feb 28;159(1):7-13. doi: 10.1016/0006-291x(89)92396-6.

DOI:10.1016/0006-291x(89)92396-6

PMID:2923625

Abstract

At 3 degrees C and pH 7.0, the addition of 40 nM ATP-G-actin to F-actin (12 microM as the monomer), polymerized in the presence of 4 mM CaCl2, determines a substantial and rapid increase of the viscosity of the solution, which is accompanied by the incorporation of the ATP-G-actin added into the polymer. The hypothesis that the presence of ATP-actin at the filament end(s) promotes the annealing reaction is substantiated by the finding that, after the addition of ATP-G-actin, the average filament length is increased. This finding is relevant, not only because it provides evidences in favour of the existence of annealing but also because it shows that the concentration of ATP-G-actin influences the filaments length distribution through a mechanism different from the elongation reaction.

摘要

在3摄氏度和pH值为7.0的条件下，向在4 mM氯化钙存在下聚合的F-肌动蛋白（以单体计为12 microM）中添加40 nM ATP-G-肌动蛋白，会使溶液粘度大幅快速增加，同时添加的ATP-G-肌动蛋白会掺入聚合物中。细丝末端存在ATP-肌动蛋白会促进退火反应这一假设，得到了以下发现的证实：添加ATP-G-肌动蛋白后，细丝平均长度增加。这一发现具有重要意义，不仅因为它为退火的存在提供了证据，还因为它表明ATP-G-肌动蛋白的浓度通过一种不同于伸长反应的机制影响细丝长度分布。