Burtnick L D, McCubbin W D, Kay C M
Can J Biochem. 1976 Jun;54(6):546-52. doi: 10.1139/o76-080.
The tropomyosin binding component (TN-T) of troponin was purified from bovine cardiac muscle using a combination of ion exchange chromatographies in the presence of urea. Sedimentation equilibrium experiments suggest a molecular weight for cardiac TN-T of 36 300 +/- 2 000, consistent with a value of 37 000 +/- 1 000 determining by polyacrylamide gel electrophoresis. Calculations based upon circular dichroism spectra indicate an apparent alpha-helical content of 43 +/- 3% for TN-T. Polyacrylamide gel electrophoresis and the effects of the calcium binding component (TN-C) upon the solubility of TN-T suggest that the two cardiac troponin components can interact with each other. Cosedimentation analysis of solutions containing cardiac tropomyosin and TN-T provide evidence for complex formation involving these two proteins. The data presented on the physical and chemical properties of TN-T, as well as the interaction studies indicate that the cardiac muscle regulatory system operates in a manner similar to that proposed for skeletal muscle.
利用在尿素存在下的离子交换色谱组合，从牛心肌中纯化了肌钙蛋白的原肌球蛋白结合成分（TN-T）。沉降平衡实验表明，心脏TN-T的分子量为36300±2000，这与通过聚丙烯酰胺凝胶电泳测定的37000±1000的值一致。基于圆二色光谱的计算表明，TN-T的表观α-螺旋含量为43±3%。聚丙烯酰胺凝胶电泳以及钙结合成分（TN-C）对TN-T溶解度的影响表明，两种心脏肌钙蛋白成分可以相互作用。对含有心脏原肌球蛋白和TN-T的溶液进行的共沉降分析为涉及这两种蛋白质的复合物形成提供了证据。所呈现的关于TN-T物理和化学性质的数据以及相互作用研究表明，心肌调节系统的运作方式与骨骼肌所提出的方式类似。
