Ishiwata S, Kondo H
Biochim Biophys Acta. 1978 Jun 21;534(2):341-9. doi: 10.1016/0005-2795(78)90017-x.
It was found that thin filaments are reconstituted from F-actin, tropomyosin and the tropomyosin binding component of troponin (TN-T) in vitro according to a self-assembly mechanism. Although a gel structure is formed when the three proteins are mixed in the order F-actin, TN-T and tropomyosin, it is in a metastable state and spontaneously transforms to dispersed filaments in an equilibrium state. The rate of the transformation is largely dependent on temperature. When the mixing order of TN-T and tropomyosin is reversed, large amounts of the complex appear immediately in the dispersed filament form. Dependence on the order of mixing is observed only when the molar ratio of TN-T to tropomyosin is about one, i.e. at the physiological ratio. When the molar ratio of TN-T to tropomyosin is either above or below one, a stable gel form or a stable dispersed filament form, was respectively, obtained independently of the mixing order of the three proteins.
研究发现，细肌丝可在体外通过自组装机制由F-肌动蛋白、原肌球蛋白和肌钙蛋白的原肌球蛋白结合成分（TN-T）重构而成。尽管当这三种蛋白质按F-肌动蛋白、TN-T和原肌球蛋白的顺序混合时会形成凝胶结构，但它处于亚稳态，并会自发转变为平衡态的分散细丝。转变速率在很大程度上取决于温度。当TN-T和原肌球蛋白的混合顺序颠倒时，大量复合物会立即以分散细丝的形式出现。只有当TN-T与原肌球蛋白的摩尔比约为1时，即处于生理比例时，才会观察到对混合顺序的依赖性。当TN-T与原肌球蛋白的摩尔比高于或低于1时，分别独立于这三种蛋白质的混合顺序，会得到稳定的凝胶形式或稳定的分散细丝形式。
