Related Experiment Video
Updated: Oct 1, 2026

Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
Published on: February 4, 2021
Effect of adenosine 5'-[beta,gamma-imido]triphosphate on myosin head domain movements
Nóra Hartvig1, Dénes Lõrinczy, Nelli Farkas
1Central Research Laboratory and Institute of Biophysics, School of Medicine, University of Pécs, Hungary.
Abstract:
Conventional and saturation transfer electron paramagnetic resonance spectroscopy (EPR and ST EPR) was used to study the orientation of probe molecules in muscle fibers in different intermediate states of the ATP hydrolysis cycle. A separate procedure was used to obtain ST EPR spectra with precise phase settings even in the case of samples with low spectral intensity. Fibers prepared from rabbit psoas muscle were labeled with isothiocyanate spin labels at the reactive thiol sites of the catalytic domain of myosin. In comparison with rigor, a significant difference was detected in the orientation-dependence of spin labels in the ADP and adenosine 5'-[beta,gamma-imido]triphosphate (AdoPP[CH2]P) states, indicating changes in the internal dynamics and domain orientation of myosin. In the AdoPP[CH2]P state, approximately half of the myosin heads reflected the motional state of ADP-myosin, and the other half showed a different dynamic state with greater mobility.
Related Concept Videos
Actin and Myosin in Muscle Contraction
Overview of Myosin Structure and Function
Mechanical Protein Functions
ATP Synthase: Mechanism
Cross-bridge Cycle
G-Protein Gated Ion Channels
Sensory organs,...
