Functional, chymotryptically split actin and its interaction with myosin subfragment 1.
Functional, chymotryptically split actin and its interaction with myosin subfragment 1.
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功能性胰凝乳裂解肌动蛋白及其与肌球蛋白亚片段 1 的相互作用。
DOI：
10.1021/bi00386a050
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发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Konno,K
中科院分区：
文献类型：
--
作者：
Konno,K
心血管研究所，加州大学，弗朗西斯科，弗朗西斯科，加州94143接收1986年6月2日;修订的Mandarin pt接收1987年1月30日摘要：我们制备了糜蛋白酶裂解的肌动蛋白，它保留了完整肌动蛋白的特征性质。G-肌动蛋白的胰凝乳蛋白酶消化产生中间35千道尔顿（kDa）片段，并由此产生称为C-末端“核心”的33 kDa的最终产物。这些片段保持与N-末端10-kDa片段连接。35-kDa-10-kDa复合物能够在加入KCl和MgCl 2后像完整的肌动蛋白一样降解，而33-kDa-10-kDa复合物则不能。35-kDa-10-kDa复合物在此称为“分裂肌动蛋白”。在僵硬状态下，分裂肌动蛋白强烈结合肌球蛋白亚片段1（S1），与完整的肌动蛋白相同的化学计量。在僵直状态下，断裂肌动蛋白与S1形成一个由N-乙酰亚胺诱导的交联产物;断裂肌动蛋白和S1上的交联位点被证明是断裂肌动蛋白的N-末端10-kDa片段和S1的20-kDa结构域。S1的50 kDa结构域和肌动蛋白的10 kDa结构域之间没有交联。因此，分裂肌动蛋白-S-1复合物的结构与完整肌动蛋白复合物的结构有些不同。断裂肌动蛋白S1的交联导致S1 ATP酶的超活化，其程度与完整肌动蛋白的交联大致相同，而未交联的断裂肌动蛋白激活S1 ATP酶的程度较低。通过氨基酸序列分析发现35-kDa片段的N-末端是残基45（瓦尔-45），因此在分裂肌动蛋白中没有残基缺失。
Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94143 Received June 2, 1986; Revised Manuscript Received January 30, 1987 abstract: We have prepared chymotryptically split actin that retains the characteristic properties of intact actin. Chymotryptic digestion of G-actin produces an intermediate 35-kilodalton (kDa) fragment and from this a final product of 33 kDa known as the C-terminal “core”. These fragments remain attached to an N-terminal 10-kDa fragment. The 35-kDa-10-kDa complex is able to polymerize upon addition of KC1 and MgCl2, like intact actin, whereas the 33-kDa-10-kDa complex is not. The 35-kDa-10-kDa complex is here termed “split actin”. In the rigor state, split actin binds to myosin subfragment 1 (Sl) strongly, with the same stoichiometry as intact actin. In the rigor state, split actin forms a carbodiimide-induced cross-linked productwith Sl; the cross-linking sites on the split actin and on Sl were proved to be the N-terminal 10-kDa fragment of split actin and the 20-kDa domain of Sl. There was no cross-linking between the 50-kDa domain of Sl and the 10 kDa of actin. Therefore, the structure of the splitactin-S-1 complex differs somewhat from that of the complex with intact actin. The cross-linking of split actinto Sl causes superactivation of Sl ATPase to approximately the same extent as does cross-linking of intact actin, whereas non-cross-linked split actin activates Sl ATPase to a lesser extent. The N-terminus of the 35-kDa fragment was found to be residue 45 (Val-45) by amino acid sequence analysis; so there is no residue missing in split actin.