Sutoh K
Biochemistry. 1980 Apr 29;19(9):1977-83. doi: 10.1021/bi00550a038.
Flash irradiation of the reconstituted troponin of thin filament complex in which one of their components, troponin C, was modified with a heterobifunctional photosensitive reagent before reconstitution of the troponin complex resulted in the formation of cross-links between troponin C and other components in contact with it. Quantitative analysis of the cross-linked products by gel electrophoresis has revealed interesting features of the quaternary structure of troponin. When the reconstituted troponin was photo-cross-linked with a xenon flash, an appreciable amount of cross-linking was detected between troponin C and troponin I and also between troponin C and troponin T. No effect of calcium on the cross-linking could be detected. This arrangement of components was found to change when troponin was complexed with F-actin-tropomyosin. The arrangement of troponin components in the thin filament complex was sensitive to calcium and magnesium; maximum cross-linking of troponin C and troponin I was observed when the thin filament was cross-linked in the presence of calcium and magnesium, while an appreciable decrease in the extent of the cross-linking was detected when calcium alone or calcium and magnesium were removed from the cross-linking medium. The cross-linking of troponin C and troponin T remained marginal irrespective of the concentration of calcium and magnesium.
在肌钙蛋白复合物重构之前，用异双功能光敏试剂对其细丝复合物的重组肌钙蛋白中的一种成分肌钙蛋白C进行修饰，然后对其进行闪光照射，结果在肌钙蛋白C与与其接触的其他成分之间形成了交联。通过凝胶电泳对交联产物进行定量分析，揭示了肌钙蛋白四级结构的有趣特征。当重组肌钙蛋白用氙闪光灯进行光交联时，在肌钙蛋白C与肌钙蛋白I之间以及肌钙蛋白C与肌钙蛋白T之间检测到了相当数量的交联。未检测到钙对交联的影响。当肌钙蛋白与F-肌动蛋白-原肌球蛋白复合时，发现这种成分排列发生了变化。细丝复合物中肌钙蛋白成分的排列对钙和镁敏感；当细丝在钙和镁存在下进行交联时，观察到肌钙蛋白C与肌钙蛋白I的最大交联，而当单独去除钙或从交联介质中去除钙和镁时，交联程度明显降低。无论钙和镁的浓度如何，肌钙蛋白C与肌钙蛋白T的交联仍然很少。
