D'Haese J, Rutschmann M, Dahlmann B, Hinssen H
Institut für Zoologie II, Universität Düsseldorf, Federal Republic of Germany.
Biochem J. 1987 Dec 1;248(2):397-402. doi: 10.1042/bj2480397.
A gelsolin-like actin-modulating protein was isolated from rat skeletal muscle and characterized with respect to its interaction with actin. The protein, with a molecular mass of approx. 85 kDa, forms a stoichiometric complex with two actin molecules and is activated by micromolar concentrations of Ca2+. It effectively severs actin filaments and promotes nucleation of actin polymerization. The activity of this protein is detectable already in crude extracts by its capability to reduce the steady state viscosity of actin. Actin-modulating activities were determined in muscle extracts of rats kept under protein catabolic conditions, i.e. as generated by corticosterone treatment and starvation. In both cases we found a marked increase of modulator activity. The possibility is discussed that the increased activity of actin modulator indicates a fragmentation of actin filaments prior to the proteolytic degradation of actin.
从大鼠骨骼肌中分离出一种类凝溶胶蛋白的肌动蛋白调节蛋白，并对其与肌动蛋白的相互作用进行了表征。该蛋白分子量约为85 kDa，与两个肌动蛋白分子形成化学计量复合物，并被微摩尔浓度的Ca2+激活。它能有效切断肌动蛋白丝并促进肌动蛋白聚合的成核作用。通过其降低肌动蛋白稳态粘度的能力，在粗提物中即可检测到该蛋白的活性。在蛋白质分解代谢条件下（即由皮质酮处理和饥饿产生）饲养的大鼠的肌肉提取物中测定了肌动蛋白调节活性。在这两种情况下，我们都发现调节活性显著增加。讨论了肌动蛋白调节因子活性增加表明在肌动蛋白蛋白水解降解之前肌动蛋白丝发生断裂的可能性。
