Price M G
Am J Physiol. 1984 Apr;246(4 Pt 2):H566-72. doi: 10.1152/ajpheart.1984.246.4.H566.
Myocardial cells contain a cytoskeleton of intermediate filaments connecting the myofibrils. The present molecular analysis of the myocardial cytoskeleton was designed to identify the intermediate filament proteins and examine their assembly properties. The intermediate filament proteins desmin and vimentin were isolated from adult bovine myocardium by sequential extraction, urea solubilization, and chromatography on hydroxylapatite and DEAE columns. Desmin was obtained virtually pure in one peak and in a mixture of desmin and vimentin in the trailing fractions. Intermediate filaments of different morphologies polymerized in the desmin and the desmin-vimentin fractions. Isolated myocardial desmin occurs as three isozymes and isolated myocardial vimentin as two isozymes, which co-migrate on two-dimensional gels with corresponding isozymes from bovine skeletal and smooth muscle. Polypeptides of 200,000 and 220,000 daltons that fractionate with myocardial desmin and vimentin are also present in cytoskeletons of smooth and skeletal muscle. The results provide direct evidence that myocardial desmin can assemble to form intermediate filaments, suggesting that desmin is the major component of the cytoskeletal filaments in cardiomyocytes.
心肌细胞含有连接肌原纤维的中间丝细胞骨架。目前对心肌细胞骨架的分子分析旨在鉴定中间丝蛋白并研究其组装特性。通过顺序提取、尿素溶解以及在羟基磷灰石和二乙氨基乙基（DEAE）柱上进行层析，从成年牛心肌中分离出中间丝蛋白结蛋白和波形蛋白。结蛋白在一个峰中几乎以纯态获得，而在拖尾部分则以结蛋白和波形蛋白的混合物形式存在。不同形态的中间丝在结蛋白部分以及结蛋白 - 波形蛋白部分聚合。分离得到的心肌结蛋白以三种同工酶形式存在，分离得到的心肌波形蛋白以两种同工酶形式存在，它们在二维凝胶上与来自牛骨骼肌和平滑肌的相应同工酶共同迁移。与心肌结蛋白和波形蛋白一起分级分离的200,000和220,000道尔顿的多肽也存在于平滑肌和骨骼肌的细胞骨架中。这些结果提供了直接证据，表明心肌结蛋白可以组装形成中间丝，这表明结蛋白是心肌细胞中细胞骨架丝的主要成分。
