[Effect of phosphorylation of light chain myosin and Ca2+ on the conformation of F-actin during skeletal muscle contraction].
The dependence of polarized fluorescence of rhodaminylphalloin specifically bound to F-actin and the tension developed by a fiber upon phosphorylation of myosin (18.5 kD) light chains as well as on the concentration of free Ca2+ was observed during the contraction of glycerinated rabbit skeletal muscle fibers. Still greater changes in the polarized fluorescence and higher values of tension were recorded for fibers with phosphorylated light chains at low (0.6 microM) Ca2+ concentrations as well as for those with dephosphorylated light chains at high (10 microM) Ca2+ concentrations. It is concluded that phosphorylation of myosin light chains modulates skeletal muscle contraction. The mechanisms of modulation involve conformational changes in F-actin.
Borovikov
Iu S
IuS
Vrotek
M
M
Lebedeva
N N
NN
Konkol'
I
I
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D005453:Fluorescence; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000378:metabolism*; D015879:Myosin Subfragments; D009218:Myosins / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D010766:Phosphorylation; D011817:Rabbits
D000199:Actins; D015879:Myosin Subfragments; D010446:Peptide Fragments; D009218:Myosins; D002118:Calcium
Vliianie fosforilirovaniia legkikh tsepeĭ miozina i Ca2+ na konformatsiiu F-aktina pri sokrashchenii skeletnykh myshts.