A novel protein phosphatase inhibitor, tautomycin Effect on smooth muscle

FEBS Letters

Han, Y.-G.³  Karaki, H.¹  Magae, J.²  Hartshorne, D.J.³  Hori, M.¹ 

[1] Department of Veterinary Pharmacology, Faculty of Agriculture, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan;Department of Bioengineering, Tokyo Institute of Technology, Meguro-ku, Tokyo 152, Japan;Muscle Biology Group, College of Agriculture, University of Arizona, Tucson, AZ 85721, USA

关键词: Tautomycin;    Protein phosphatase inhibitor;    Smooth muscle contraction;   

DOI  :  10.1016/0014-5793(91)80745-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The antibiotic, tautomycin, was found to be a potent inhibitor of protein phosphatases and equally effective for the type-1 and type-2A enzymes. For the catalytic subunits of the type-1 and type-2A phosphatases the IC₅₀ value was 22 to 32 nM. For the phosphatase activity present in chicken gizzard actomyosin the IC₅₀ value was 6 nM. Tautomycin had no effect on myosin light chain kinase activity. Tautomycin induced a Ca²⁺-independent contraction of intact and permeabilized smooth muscle fibers and this was accompanied by an increase in the level of myosin phosphorylation. Thus, tautomycin by virtue of its ability to inhibit phosphatase activity is a valuable addition for studying the role of protein phosphorylation.

【 授权许可】

Unknown