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Updated: Aug 12, 2026

Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
Published on: February 4, 2021
High affinity of various smooth muscle myosins for skeletal F-actin demonstrated by enzyme kinetics and electron
Abstract:
Myosins isolated from mixed rabbit skeletal muscle and several smooth muscles differ with respect to the rate of ATP hydrolysis and the degree of inhibition of the potassium-activated ATPase activity at saturating actin concentrations. Kinetic studies indicate that smooth muscle myosins are tightly bound to skeletal F-actin in the presence of ATp. This observation led to the hypothesis that ATP is a poor dissociating agent for smooth muscle myosin and skeletal F-actin. The kinetic interpretation was verified by electron microscopic observations of myosin binding to F-actin filaments in the presence of ATP.
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