Effect of 67 kDa calcimedin on caldesmon functioning

FEBS Letters

Gusev, Nikolai B.²  Panaiotov, Michail P.²  Vorotnikov, Alexander V.¹  Bogatcheva, Natalia V.² 

[1] National Cardiology Research Centre of Russia, Moscow 121552, Russian Federation;Department of Biochemistry, School of Biology, Moscow State University, Moscow 119899, Russian Federation

关键词: Caldesmon;    Calcimedin;    Calmodulin;    Troponin C;    S-100;    DFDNB-1;    3-difluoro-4;    6-dinitrobenzene;    EDC;    1-ethyl-3-(3-dimethylaminopropyl)carbodiimide;    NHS;    N-hydroxysuccinimide;    PMSF;    phelylmethanesulfonylfluoride;    SDS;    sodium dodecyl sulphate;   

DOI  :  10.1016/0014-5793(93)80728-D

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Interaction of smooth muscle caldesmon with calmodulin, troponin C, S-100 protein and 67 kDa calcimedin was analyzed. Native gel electrophoresis and crosslinking revealed the complex formation between caldesmon and three EF-hand Ca-binding proteins, whereas calcimedin did not interact with caldesmon. In the presence of Ca²⁺, calcimedin binds to actin-tropomyosin without affecting the interaction of caldesmon with this complex. Although calcimedin reversed the inhibitory action of caldesmon on the actomyosin ATPase activity at a lower concentration than three other Ca-binding proteins, this effect only slightly depends on Ca²⁺ and was observed at the concentration of calcimedin comparable to that of actin. It is concluded that calcimedin itself cannot be responsible for Ca-dependent regulation of caldesmon functioning, but actin bundling induced by calcimedin (or by other actin binding proteins) decreases the inhibitory action of caldesmon on the actomyosin ATPase activity.

【 授权许可】

Unknown