Tanokura M, Ohtsuki I
J Biochem. 1984 May;95(5):1417-21. doi: 10.1093/oxfordjournals.jbchem.a134749.
The binding of various combinations of chymotryptic troponin T subfragments, troponin I and troponin C to tropomyosin, troponin C and troponin I was examined semiquantitatively by using affinity chromatography. The interaction between troponin T2 and troponin I intensified the interaction between troponin T2 (or troponin T) and tropomyosin. When a mixture of troponin T2 and troponin C was applied to a tropomyosin-Sepharose 4B column, neither troponin T2 nor troponin C was retained in the presence of Ca2+ ion, while only troponin T2 was bound in the absence of Ca2+ ion. Such a Ca2+-dependent effect was not observed with troponin T. Troponin T2 subfragments, except troponin T2 beta III, were retained by troponin C-Sepharose 4B in the presence of troponin I, even in the solution containing 1.0 M NaCl, in the presence and absence of Ca2+ ion. On the basis of these findings, the interactions among troponin components and tropomyosin are discussed.
通过亲和色谱法对胰凝乳蛋白酶原肌钙蛋白T亚片段、肌钙蛋白I和肌钙蛋白C的各种组合与原肌球蛋白、肌钙蛋白C和肌钙蛋白I的结合进行了半定量检测。肌钙蛋白T2和肌钙蛋白I之间的相互作用增强了肌钙蛋白T2（或肌钙蛋白T）与原肌球蛋白之间的相互作用。当将肌钙蛋白T2和肌钙蛋白C的混合物应用于原肌球蛋白-琼脂糖4B柱时，在Ca2+离子存在的情况下，肌钙蛋白T2和肌钙蛋白C均未被保留，而在没有Ca2+离子的情况下只有肌钙蛋白T2被结合。肌钙蛋白T未观察到这种Ca2+依赖性效应。除肌钙蛋白T2βIII外，肌钙蛋白T2亚片段在肌钙蛋白I存在的情况下，即使在含有1.0M NaCl的溶液中，无论有无Ca2+离子，均被肌钙蛋白C-琼脂糖4B保留。基于这些发现，讨论了肌钙蛋白各组分与原肌球蛋白之间的相互作用。
