Takahashi K, Nakamura F, Hattori A, Yamanoue M
J Biochem. 1985 Apr;97(4):1043-51. doi: 10.1093/oxfordjournals.jbchem.a135146.
A protein component which is released from skeletal-muscle myofibrils on the treatment with Ca2+ at concentrations above 10(-5) M and modifies the actin-myosin interaction was purified by a method involving column chromatography on Sephadex G-200 and DEAE-cellulose in succession. Although this protein resembles tropomyosin in some physicochemical properties, it has the same chain weight of 34,000 as the alpha-component of tropomyosin on SDS-polyacrylamide gel electrophoresis, and differed from tropomyosin not only in the amino acid composition but also in prolonging the clearing phase of superprecipitation of reconstituted actomyosin. We therefore concluded that this protein is a new myofibrillar one, and termed it "paratropomyosin." In postrigor muscle, it seems likely that paratropomyosin is released from its original locus with an increased concentration of Ca2+, and that it weakens rigor linkages formed between actin and myosin.
一种蛋白质成分，在浓度高于10⁻⁵M的Ca²⁺处理下从骨骼肌肌原纤维中释放出来，并改变肌动蛋白-肌球蛋白相互作用，通过依次在Sephadex G - 200和DEAE - 纤维素柱上进行柱色谱法进行纯化。尽管这种蛋白质在某些物理化学性质上类似于原肌球蛋白，但在SDS - 聚丙烯酰胺凝胶电泳上它具有与原肌球蛋白α成分相同的34,000链重，并且不仅在氨基酸组成上与原肌球蛋白不同，而且在延长重组肌动球蛋白超沉淀的澄清阶段方面也不同。因此，我们得出结论，这种蛋白质是一种新的肌原纤维蛋白，并将其命名为“副原肌球蛋白”。在死后僵硬肌肉中，副原肌球蛋白似乎可能随着Ca²⁺浓度的增加从其原始位置释放出来，并且它会削弱肌动蛋白和肌球蛋白之间形成的僵硬连接。
