Diverse actions of cadmium on the smooth muscle myosin phosphorylation system

FEBS Letters

Kostrzewska, Anna¹  Sobieszek, Apolinary¹ 

[1] Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg, Austria and Institute of Obstetrics and Gynecology, Medical Academy, Bialystok, Poland

关键词: Myosin light chain phosphorylation;    Calmodulin-Ca2+ complex;    Cadmium;    Smooth muscle;   

DOI  :  10.1016/0014-5793(90)81419-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The effects of cadmium (Cd) on smooth muscle myosin phosphorylation have been investigated using an in vitro system comprising myosin filaments containing endogenous calmodulin (CM) and myosin light chain kinase (MLCKase). In the absence of calcium (Ca), Cd as well as some other divalent cations caused no activation of phosphorylation. However, when at least one (or possibly two) Ca²⁺ were bound per CM, the addition of 10 μM to 40 μM Cd²⁺ resulted in a 2 to 3 fold acceleration of the phosphorylation rate. Higher Cd concentrations caused inhibition of the system independent of Ca²⁺ concentration through the formation of Cd-ATP complexes. These results explain some previously controversial data on the complex effects of Cd in intact smooth muscles.

【 授权许可】

Unknown