Kögler H, Moir A J, Trayer I P, Rüegg J C
II. Physiologisches Institut, Universität Heidelberg, Germany.
FEBS Lett. 1991 Dec 2;294(1-2):31-4. doi: 10.1016/0014-5793(91)81336-7.
The amino-terminal region of actin participates in the binding of myosin subfragment 1 (S1) during cross-bridge cycling, thereby assisting in the activation of the magnesium-dependent myosin ATPase. Effects of three actin fragments on the magnesium-dependent S1 and acto-S1 ATPase activities in solution were studied. One of the peptides, containing residues actin 1-44, mimicked the S1 ATPase-activating properties of actin and in turn inhibited acto-S1 ATPase both in a concentration-dependent manner. This suggests peptide competition for the actin binding site on myosin. The other fragments, residues actin 1-18 and 82-119, respectively, had no detectable effect on S1- and acto-S1 ATPase activity.
肌动蛋白的氨基末端区域在横桥循环过程中参与肌球蛋白亚片段1（S1）的结合，从而有助于激活镁依赖性肌球蛋白ATP酶。研究了三种肌动蛋白片段对溶液中镁依赖性S1和肌动蛋白-S1 ATP酶活性的影响。其中一种肽包含肌动蛋白1 - 44位残基，模拟了肌动蛋白的S1 ATP酶激活特性，进而以浓度依赖性方式抑制肌动蛋白-S1 ATP酶。这表明该肽与肌球蛋白上的肌动蛋白结合位点存在竞争。另外两个片段，分别为肌动蛋白1 - 18位残基和82 - 119位残基，对S1和肌动蛋白-S1 ATP酶活性没有可检测到的影响。
