Inhibition of 20‐kDa myosin light chain exchange by monoclonal antibodies against 17‐kDa myosin light chain

FEBS Letters

Higashihara, Masaaki²  Ikebe, Mitsuo¹ 

[1] Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA;First Department of Internal Medicine, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan

关键词: Smooth muscle myosin;    20-kDa myosin light chain;    Monoclonal antibody;   

DOI  :  10.1016/0014-5793(95)00280-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two anti-17,000 Da myosin light chain (LC17) monoclonal antibodies (MM2 and MM10), which increase the actin-activated Mg²⁺-ATPase activity of dephosphorylated smooth muscle myosin, inhibited the exchange of the 20,000 Da regulatory light chain of myosin (LC20). MM2, which shows higher potency of activation of ATPase activity, inhibited the exchange more extensively than MM10, suggesting that there is a correlation between the activation of ATPase activity and the inhibition of the LC20 exchange. The inhibition of the exchange was observed for intact myosin and heavy meromyosin but not subfragment 1, suggesting that the heavy chain at the head—rod junction is involved in the inhibition of LC20 exchange by anti-LC17 antibodies. Alternatively, the interaction between the two heads of the myosin molecule may influence the inhibition of LC20 exchange. These results suggest that LC20 interacts with both LC17 and the heavy chain, and the interaction between LC20 and LC17 is involved in the activation of actin-activated ATPase activity of smooth muscle myosin.

【 授权许可】

Unknown