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A novel protein phosphatase inhibitor, tautomycin Effect on smooth muscle
Author(s) -
Hori M.,
Magae J.,
Han Y.-G.,
Hartshorne D.J.,
Karaki H.
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)80745-o
Subject(s) - phosphatase , myosin light chain kinase , phosphorylation , myosin light chain phosphatase , biochemistry , gizzard , myosin , chemistry , enzyme , alkaline phosphatase , kinase , biology , paleontology
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 IC 50 value was 22 to 32 nM. For the phosphatase activity present in chicken gizzard actomyosin the IC 50 value was 6 nM. Tautomycin had no effect on myosin light chain kinase activity. Tautomycin induced a Ca 2+ ‐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.