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Thiophosphorylation of myosin light chain increases rigor stiffness of rabbit smooth muscle
Author(s) -
Khromov A. S.,
Somlyo A. V.,
Somlyo A. P.
Publication year - 1998
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1998.345be.x
Subject(s) - myosin , myosin light chain kinase , chemistry , biophysics , stiffness , phosphorylation , muscle stiffness , muscle contraction , immunoglobulin light chain , anatomy , biochemistry , biology , materials science , antibody , immunology , composite material
1 The effect of thiophosphorylation of the regulatory myosin light chain (MLC 20 ) on rigor stiffness was determined in permeabilized rabbit bladder smooth muscle. 2 Rigor stiffness of α‐toxin‐permeabilized smooth muscle was significantly increased by thiophosphorylation of MLC 20 . This increase may have been due to partial shortening (melting) in the proximal rod region and/or stiffening of the regulatory domain of the myosin head. 3 We suggest that phosphorylation of MLC 20 , by increasing the stiffness of the S1 lever arm and/or S2 hinge regions of the myosin molecule, favours separation of the two phosphorylated heads and consequent deinhibition of motor domain activity.