Interaction of trifluoperazine with Tetrahymena calmodulin

FEBS Letters

Muto, Yoshinori²  Nozawa, Yoshinori²  Hatano, Masahiro¹  Shimizu, Toru¹ 

[1] Chemical Research Institute of Non-Aqueous Solutions, Tohoku University, Sendai 980, Japan;Department of Biochemistry, Gifu University School of Medicine, Gifu 500, Japan

关键词: Trifluoperazine;    Tetrahymena;    Calmodulin;    19F NMR;    Tet. CaM;    calmodulin purified from Tetrahymena pyriformis;    CaM;    calmodulin;    TFP;    trifluoperazine;    CD;    circular dichroism;    SIS;    solvent-induced shift;   

DOI  :  10.1016/0014-5793(84)80115-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have used ¹⁹F NMR to study interactions of trifluoperazine (TFP), a potent calmodulin (CaM) antagonist, with Tetrahymena calmodulin (Tet. CaM). Changes in chemical shift and bandwidth of TFP caused by adding Tet. CaM in the presence of excess Ca²⁺ were much smaller than those by adding porcine CaM. The spectral features of the TFP—Tet. CaM solution in the presence of excess Ca²⁺ were quite similar to those of the TFP—porcine CaM solution in the absence of Ca²⁺. The exchange rate of TFP from Tet. CaM was estimated to be nearly 20 s⁻¹. The TFP—Tet. CaM solution in the absence of Ca²⁺ showed a pronounced pH dependence of the ¹⁹F NMR chemical shift, whereas the solution in the presence of excess Ca²⁺ showed a smaller pH dependence. Thus, it was suggested that TFP is located near a hydrophilic region of the Tet. CaM molecule in the absence of Ca²⁺, while TFP is located near a hydrophobic region of the Tet. CaM in the presence of excess Ca²⁺.

【 授权许可】

Unknown