Levitsky D I, Shuvalova L A, Poglazov B F
FEBS Lett. 1987 Aug 31;221(1):77-80. doi: 10.1016/0014-5793(87)80355-1.
It has been shown that in the absence of KCl, the actin-stimulated Mg2+-ATPase activity of rabbit skeletal myosin minifilaments with phosphorylated regulatory lights chains (LC2) exceeds 3-4-fold that of myosin minifilaments with dephosphorylated LC2. Addition of KCl leads to a decrease in the difference between the two ATPase activities. LC2 phosphorylation considerably increases the rate of ATPase reaction and only slightly decreases the affinity of myosin minifilaments for F-actin. It is suggested that the unusual effect of LC2 phosphorylation on the kinetic parameters of the actin-stimulated ATPase reaction of myosin minifilaments can be accounted for by its influence on the interaction between myosin heads which results in the ordered self-assembly of minifilaments.
研究表明，在没有氯化钾的情况下，具有磷酸化调节轻链（LC2）的兔骨骼肌肌球蛋白微丝的肌动蛋白刺激的Mg2 + -ATP酶活性比具有去磷酸化LC2的肌球蛋白微丝的活性高3至4倍。添加氯化钾会导致两种ATP酶活性之间的差异减小。LC2磷酸化显著提高了ATP酶反应的速率，并且仅略微降低了肌球蛋白微丝对F-肌动蛋白的亲和力。有人认为，LC2磷酸化对肌球蛋白微丝的肌动蛋白刺激的ATP酶反应动力学参数的异常影响，可以通过其对肌球蛋白头部之间相互作用的影响来解释，这种相互作用导致微丝的有序自组装。
