Catch contraction of bivalve adductor muscle by "Catch proteins"

通过“Catch 蛋白质”捕获双壳类内收肌的收缩

基本信息

批准号：
02806040
负责人：
OJIMA Takao
金额：
$ 1.28万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02806040/
关键词：
bivalves adductor muscles catch contraction actin-bindin proteins アクチン結合タンパク質

项目摘要

It is well-known that bivalve smooth adductor muscle show catch contraction, that is, an energy-saving prolonged state of contraction. In the present project, we have studied the catch mechanism from the standpoint of the participation of regulatory proteins in the catch contraction.1. Surf-clam smooth muscle was investigated to isolate the troponin and other actin-binding proteins. This muscle seemed to lack troponin because its native thin filament and troponin fraction were incapable of conferring Ca^<2+>-sensitivity to rabbit actomyosin. However, the foot muscle possesses major 160kDa actin binding protein (ABP) which was cosedimented with actin to form turbidity. The ABP was shown to make F-cactin filaments into bundiles under physiological conditions. The molecular weight and actin-bunding property of the ABP were similar to those of caldesmon which has been considered as a candidate for "latch proteins" in vertebrate smooth muscle, however, the other characteristics of ABP were … More not. Thus, the binding of ABP to F-actin was unaffected by Ca^<2+>-calmodulin and the amino acid composition of the ABP was quite different from that of caldesmon. These resu lts indicate that the APB is a different type of actin-bundling protein from caldesmon. The ABP-like proteins were shown to be present in various bivalves, such as scallop, mussel, oyster, and ribbed ark. To make clear the relationship between the actin-bundling property of ABP and the catch contraction, further physiological and biochemical studies are necessary.2. A binary complex consisting of 19kDa troponin-I(19-Tnl)and 4OkDa troponin-T(40-TnT)was co-purified with troponin form a crude troponin fraction of akazara scallop adductor muscle. This complex is incapable of conferring Ca^<2+>-sensitivity to rabbit reconstituted actomyosin Mg-ATPase activity, but became capable on further complexing with Akazara scallop troponin-C. On hybridization with the Akazara scallop troponin subunits, the isolated 19-Tnl and 40-TnT were shown to be able to substitute for troponin-I and troponin-T, respectively. We may consider that the 19-TnIAO-Tnl binary complex is implicated in the actin-finked regulation in somehow different manner from troponin. Less

众所周知，双壳平滑的加法肌肉表现出收缩收缩，即节能的长时间收缩状态。在本项目中，我们从调节蛋白参与捕获收缩的角度研究了捕获机制。1。研究了冲浪 - 环境平滑肌，以分离肌钙蛋白和其他肌动蛋白结合蛋白。这种肌肉似乎缺乏肌钙蛋白，因为它的天然细丝和肌钙蛋白分数无法赋予Ca^<2+> - 对兔肌动蛋白的敏感性。但是，脚肌肉具有主要的160kDa肌动蛋白结合蛋白（ABP），并用肌动蛋白染色以形成浊度。显示ABP在物理条件下使F-甲有醇丝变成束。 ABP的分子量和肌动蛋白捆绑特性类似于Caldesmon的分子量，而Caldesmon被认为是脊椎动物平滑肌中“闩锁蛋白”的候选者，但是，ABP的其他特征是……而不是。这就是ABP与F-肌动蛋白的结合不受Ca^<2+> - 钙调蛋白的影响，而ABP的氨基酸组成与Caldesmon的氨基酸组成完全不同。这些resu lts表明APB是Caldesmon的另一种类型的肌动蛋白捆绑蛋白。显示出ABP样蛋白存在于各种双壳类中，例如扇贝，贻贝，牡蛎和肋骨方舟。为了清除ABP的肌动蛋白捆绑特性与捕获收缩之间的关系，需要进一步的物理和生化研究。2。由19KDA肌钙蛋白I（19-TNL）和4OKDA Troponin-T（40-TNT）组成的二进制复合物与肌钙蛋白形成Akazara扇贝助剂的粗肌蛋白分数。该复合物无法赋予Ca^<2+> - 对兔重构肌动蛋白Mg-ATPase活性的敏感性，但能够与Akazara scallop troponin-c进一步复杂化。在与Akazara扇贝肌钙蛋白亚基杂交时，孤立的19-TNL和40-TNT可分别替代肌钙蛋白I和troponin-T。我们可能会认为，19-TNIAO-TNL二元复合物在与肌动蛋白不同的方式中实施了与肌动蛋白的调节。