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Updated: Aug 12, 2026

Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
Published on: February 4, 2021
Bidirectional functional communication between myosin subfragments 1 and 2 in skeletal muscle fibers
T Kobayashi1, S Kosuge, H Sugi
1Department of Physiology, School of Medicine, Teikyo University, Tokyo, Japan.
Abstract:
It has been shown that polyclonal antibody directed against myosin subfragment 2 (S-2) eliminates Ca(2+)-activated isometric force development in glycerinated skeletal muscle fibers while Mg-ATPase activity of the fibers remains unchanged. To further explore possible involvement of myosin S-2 in muscle contraction, we studied the effect of anti-S-2 antibody on rigor linkage formation in the fibers, and found that the antibody inhibited development of rigor force in a dose- and time-dependent manner without changing the relation between muscle fiber stiffness and force. If, however, the antibody was applied after development of rigor force, it had no effect on both the stiffness and force. These results strongly suggest bidirectional functional communication between myosin subfragments 1 and 2 in the fibers.
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