Disassembly and reconstitution of the Ca2+‐sensitive thin filaments of vascular smooth muscle

FEBS Letters

Smith, Christopher W.J.¹  Marston, Steven B.¹ 

[1] Cardiothoracic Institute, 2 Beaumont Street, London WIN 2DX, England

关键词: Smooth;    muscle;    Ca2+;    regulation;    Calmodulin;    Caldesmon;    Actin;    Tropomyosin;   

DOI  :  10.1016/0014-5793(85)80665-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The Ca²⁺-sensitive thin filaments of aorta smooth muscle have been, disassembled into their constituent proteins, actin, tropomyosin and a 120-kDa protein. The 120-kDa protein bound to aorta actin-tropomyosin and inhibited its ability to activate myosin MgATPase. This inhibition correlated with the binding of one 120-kDa protein molecule per 29 actin monomers. Upon the addition of calmodulin to the actintropomyosin-120-kDa protein complex, the inhibition was relieved in 10⁻⁴ M Ca²⁺ but not 10⁻⁹ M Ca²⁺. The full release of inhibition was not accompanied by a full release of 120-kDa protein binding to actintropomyosin. A fully active, Ca²⁺-sensitive aorta thin filament has thus been reconstituted from just four components: actin, tropomyosin, 120-kDa protein and calmodulin.

【 授权许可】

Unknown