Assulin O, Werber M M, Muhlrad A
FEBS Lett. 1986 Mar 3;197(1-2):328-34. doi: 10.1016/0014-5793(86)80351-9.
Limited proteolysis has been used to study the influence of actin, in the absence or presence of regulatory proteins of the thin filament (tropomyosin and troponin), as well as that of the myofibrillar structure on the tryptic cleavage of the heavy meromyosin (HMM)/light meromyosin (LMM) hinge region in myosin heavy chain. Cleavage at the HMM/LMM hinge is almost absent in myofibrils, whereas this hinge is accessible to tryptic digestion in actomyosin, in native thin filaments attached to myosin and in myosin heavy chain alone. This observation indicates that it is the myofibrillar structure which profoundly affects the tryptic accessibility of this specific hinge region of myosin. This provides a good example of the manner by which a highly organized supramolecular structure might affect the chemical properties of a specific site in a macromolecule.
有限蛋白水解已被用于研究在不存在或存在细肌丝调节蛋白（原肌球蛋白和肌钙蛋白）的情况下肌动蛋白的影响，以及肌原纤维结构对肌球蛋白重链中重酶解肌球蛋白（HMM）/轻酶解肌球蛋白（LMM）铰链区胰蛋白酶切割的影响。在肌原纤维中，HMM/LMM铰链处几乎没有切割，而在肌动球蛋白、附着于肌球蛋白的天然细肌丝以及单独的肌球蛋白重链中，该铰链可被胰蛋白酶消化。这一观察结果表明，是肌原纤维结构深刻影响了肌球蛋白这一特定铰链区的胰蛋白酶可及性。这为高度组织化的超分子结构可能影响大分子中特定位点化学性质的方式提供了一个很好的例子。
