INTERACTION OF ALPHA-ACTININ AND NEBULIN INVITRO - SUPPORT FOR THE EXISTENCE OF A 4TH FILAMENT SYSTEM IN SKELETAL-MUSCLE
INTERACTION OF ALPHA-ACTININ AND NEBULIN INVITRO - SUPPORT FOR THE EXISTENCE OF A 4TH FILAMENT SYSTEM IN SKELETAL-MUSCLE
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DOI：
10.1016/0014-5793(90)81144-d
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发表时间：
1990-08-20
期刊：
影响因子：
3.5
通讯作者：
WEBER, K
中科院分区：
文献类型：
--
作者：
NAVE, R;FURST, DO;WEBER, K
星云蛋白是一种高分子量多肽（质量60 - 80万），占骨骼肌肌原纤维质量的3%。由于其在天然条件下难以提取，对其生物化学性质的了解相对较少。本文报道了α-肌动蛋白（一种主要的z线蛋白）与星云蛋白的体外结合。经十二烷基硫酸钠溶解后，凝胶电泳分离的肌纤维多肽在硝化纤维素上印迹，用125i标记的α-肌动蛋白探针，星云蛋白是唯一被α-肌动蛋白修饰的多肽。这一结果为基于最近的免疫电子显微图的假设提供了生化支持，即星云可能在骨骼肌中形成第四纤维系统，可能延伸到z线。
Nebulin is a high molecular weight polypeptide (mass 0.6–0.8 million) which accounts for 3% of the myofibrillar mass in skeletal muscle. Due to its resistance to extraction under native conditions, relatively little is known about the biochemistry of the molecule. Here we report in vitro binding of α-actinin (a major Z-line protein) to nebulin. After solubilization with sodium dodecylsulfate myofibrillar polypeptides separated by gel electrophoresis were blotted on nitrocellulose and probed with125I-labelled α-actinin, Nebulin is the only polypeptide decorated by α-actinin. This result gives biochemical support for the hypothesis, based on recent immunoelectron micrographs, that nebulin could form in skeletal muscle a fourth filament system, possibly extending to the Z-line.