肌球蛋白微丝在高压力下的解离和重组

DISSOCIATION REASSEMBLY MYOSIN MINIFILAMENT INDUCED BY HIGH HYDROSTATIC PRESSURE

高压力下肌球蛋白微丝（ｍｙｏｓｉｎｍｉｎｉｆｉｌａｍｅｎｔ）的解离研究表明，在１—６５０ｂａｒ压力下肌球蛋白微丝的解离是完全可逆的，在５℃时其解离平衡常数的对数ｌｇＫ＝－１２９，解离标准体积变化为－２０８８ｍｌ／ｍｏｌ。研究还指出，由肌球蛋白聚合成肌球蛋白微丝的熵是＋１４８．５ｋｃａｌ／ｍｏｌ（２０℃），表明这是一熵驱动的自发过程。连续二次加压解离动力学研究结果暗示，肌球蛋白二体是肌球蛋白微丝解离过程中的中间体。

The studies on the dissociation of myosin minifilament by high hydrostatic pressure indicated that the dissociation of myosin minifilament into myosin at pressure 1-650 bar was entirely reversible. The logarithm of dissodation constant of minimament at 5℃, 1gK, was determin as-129, and the standard volume change upon dissociation was -2088ml/mol. The studies also indicated that the entropy of association of minifilament from myosin was +148.5kcal/mol (20℃), implying that the association was driven by entropy. The dynamics of dissociation of minifilament upon two successive rapid rise in pressure indicated that myosin dimer would be the intermediate in the dissodation of minifilament.