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

• 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

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，双壳类平滑内收肌表现出捕捉性收缩，即一种节能的长时间收缩状态。在本项目中，我们从调节蛋白参与catch收缩的角度研究了catch机制。 1．研究了北蛤平滑肌以分离肌钙蛋白和其他肌动蛋白结合蛋白。该肌肉似乎缺乏肌钙蛋白，因为其天然细丝和肌钙蛋白部分不能赋予兔肌动球蛋白Ca 2+ -敏感性。然而，足部肌肉具有主要的160kDa肌动蛋白结合蛋白(ABP)，其与肌动蛋白共沉淀形成浑浊。在生理条件下，ABP 可使 F-仙人掌丝形成束。 ABP 的分子量和肌动蛋白结合特性与 caldesmon 相似，caldesmon 被认为是脊椎动物平滑肌中“闩锁蛋白”的候选者，然而，ABP 的其他特征却不然。因此，ABP与F-肌动蛋白的结合不受Ca 2+ -钙调蛋白的影响，并且ABP的氨基酸组成与caldesmon的氨基酸组成完全不同。这些结果表明 APB 是与 caldesmon 不同类型的肌动蛋白捆绑蛋白。研究表明，ABP 样蛋白存在于各种双壳类动物中，如扇贝、贻贝、牡蛎和罗纹方舟。为了明确ABP的肌动蛋白成束特性与catch收缩之间的关系，需要进一步的生理生化研究。2．由 19kDa 肌钙蛋白-I(19-Tnl) 和 40kDa 肌钙蛋白-T(40-TnT) 组成的二元复合物与肌钙蛋白共同纯化，形成 akazara 扇贝内收肌的粗肌钙蛋白部分。该复合物不能赋予兔重构肌动球蛋白Mg-ATP酶活性Ca 2+ -敏感性，但能够与Akazara扇贝肌钙蛋白-C进一步复合。与 Akazara 扇贝肌钙蛋白亚基杂交后，分离的 19-TnI 和 40-TnT 被证明能够分别替代肌钙蛋白-I 和肌钙蛋白-T。我们可以认为 19-TnIAO-Tnl 二元复合物以某种与肌钙蛋白不同的方式参与肌动蛋白连接的调节。较少的

项目成果

Takao Ojima and Kiyoyoshi Nishita: "Comparative studies on biochemical characteristics of troponins from ezo-giant scallop and akazara scallpo." Comp. Biochem. Physiol.(1992)

Takao Ojima 和 Kiyoyoshi Nishita：“扇贝和赤扇贝肌钙蛋白生化特性的比较研究”。

Takao Ojima&Kiyoyoshi Nishita: "Comparative studies on biochemical characteristics of troponins from ezoーgiant scallop and akazara scallop." Submitted to Comparative Biochemistry and Physiology. (1992)

Takao Ojima 和 Kiyoyoshi Nishita：“来自 ezogiant 扇贝和 akazara 扇贝的肌钙蛋白生化特性的比较研究”，提交给《比较生物化学和生理学》（1992 年）。

Satoru Chiba,Takao Ojima,& Kiyoyoshi Nishita: "Preparation and partial characterization of a novel actin-binding protein from surf-clam foot muscle." Nippon Suisan Gakkaishi. (1992)

千叶悟、小岛贵夫、

Satoru Chiba,Takao Ojima,&kiyoyoshi Nishita: "Preparation and partial characterization of a novel actinーbinding protein from surfーclam foot muscle." Submitted to Nippon Suisan Gakkaishi. (1992)

Satoru Chiba、Takao Ojima 和 kiyoyoshi Nishita：“来自海蛤足部肌肉的新型肌动蛋白结合蛋白的制备和部分表征”，提交给 Nippon Suisan Gakkaishi（1992 年）。