Damage to actin filaments by glutaraldehyde: protection by tropomyosin.
Damage to actin filaments by glutaraldehyde: protection by tropomyosin.
复制标题
DOI：
10.1083/jcb.90.2.459
复制
发表时间：
1981-08
影响因子：
7.8
通讯作者：
Lehrer, S S
中科院分区：
文献类型：
--
作者：
Lehrer, S S
F-肌动蛋白和F-肌动蛋白-原肌球蛋白复合物与20 mM戊二醛在0 ℃和25 ℃下反应19-22 h，产生广泛交联的细丝，如通过十二烷基硫酸钠（SDS）聚丙烯酰胺凝胶电泳所判断。电子显微照片显示，与存在原肌球蛋白或未处理的对照相比，在不存在原肌球蛋白的情况下，戊二醛处理的F-肌动蛋白的纤维更短，更不规则。与未处理的对照相比，戊二醛处理的F-肌动蛋白溶液的粘度下降40%，但戊二醛处理的F-肌动蛋白-原肌球蛋白复合物溶液的粘度增加90%，表明交联的不同效果。SDS凝胶表明，亚基内交联被引入F-肌动蛋白，当原肌球蛋白存在时，分子内交联的形成被抑制。当在相似或更温和的反应条件下将分子内交联引入G-肌动蛋白时，盐诱导的G的抑制导致F聚合结果。这些数据表明，在广泛的F-肌动蛋白丝交联（固定）发生的条件下，由于同时形成的亚基内交联，导致局部解聚和扭曲，原肌球蛋白保护这种损害的细丝成为损坏。
Reaction of F-actin and the F-actin-tropomyosin complex with 20 mM glutaraldehyde for 19-22 h at 0 degrees C and 25 degrees C results in extensively cross-linked filaments, as judged by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Electron micrographs show shorter, more irregular filaments for glutaraldehyde-treated F-actin in the absence of tropomyosin as compared to the presence of tropomyosin or untreated controls. There was a 40% drop in viscosity of glutaraldehyde-treated F-actin solutions but a 90% increase in viscosity for the glutaraldehyde-treated F-actin-tropomyosin complex in solution, as compared to the untreated controls, indicating different effects of cross-linking. SDS gels indicate that intrasubunit cross- links are introduced into F-actin and that when tropomyosin is present, intramolecular cross-link formation is inhibited. Inhibition of the salt-induced G leads to F polymerization results when intramolecular cross-links are introduced into G-actin under similar or milder reaction conditions. These data indicate that, under conditions for which extensive F-actin filament cross-linking (fixing) occurs, the filaments become damaged due to the concurrent formation of intrasubunit cross-links that cause local depolymerization and distortion and that tropomyosin protects against this damage.