Woodhead J L, Lowey S
J Mol Biol. 1983 Aug 25;168(4):831-46. doi: 10.1016/s0022-2836(83)80077-1.
Two proteins reported to be located in the M-band of skeletal muscle are M-protein (Mr 160,000) and creatine kinase (Mr 83,000). We have isolated and purified these proteins from adult chicken pectoralis muscle, and have studied their in vitro interactions with myosin, heavy meromyosin, light meromyosin and subfragment-2 in order to obtain a fuller understanding of the role these proteins play in the M-band of skeletal muscle. Experiments using the techniques of analytical ultracentrifugation, affinity chromatography and electron microscopy were carried out near physiological pH and ionic strength, under which conditions the M-band proteins are known to be firmly bound to the myofibril in situ. The results of our studies indicate that such interactions are either weak or absent in vitro. Discrepancies between our results and those from several other studies are discussed. We conclude that additional components may be required in order to observe interactions in vitro which are similar to those present in the intact myofibril.
据报道，位于骨骼肌M带的两种蛋白质是M蛋白（分子量160,000）和肌酸激酶（分子量83,000）。我们已从成年鸡胸大肌中分离并纯化了这些蛋白质，并研究了它们在体外与肌球蛋白、重酶解肌球蛋白、轻酶解肌球蛋白和亚片段2的相互作用，以便更全面地了解这些蛋白质在骨骼肌M带中所起的作用。在接近生理pH值和离子强度的条件下进行了使用分析超速离心、亲和色谱和电子显微镜技术的实验，已知在这些条件下M带蛋白在原位与肌原纤维紧密结合。我们的研究结果表明，此类相互作用在体外要么很弱，要么不存在。讨论了我们的结果与其他几项研究结果之间的差异。我们得出结论，可能需要其他成分才能在体外观察到与完整肌原纤维中相似的相互作用。
