Protein Chemistry. Structure, Properties, Research Methods - Shendryk A.N. 2022

Proteins of blood and muscle tissues
Proteins of the contractile system
Functions of muscle tissue proteins - Actomyosin

Mixing Myosin and Actin yields a complex known as Actomyosin. This complex formation is accompanied by an increase in both viscosity and Flow Birefringence. The composition and Molecular Weight of actomyosin vary significantly depending on pH, the concentration of K and Mg salts, protein content, and several other experimental conditions. Actomyosin is extracted from Muscle tissue through prolonged incubation with 0.6 M KCl. The ratio of G-actin to myosin in the actomyosin complex typically ranges around 1:1. A key characteristic of the actomyosin complex is its ability to dissociate in the presence of ATP and Mg2+ ions. This dissociation is accompanied by a sharp decrease in the viscosity of the actomyosin solution.

The dissociation of the complex is accompanied by the Hydrolysis of ATP. The dissociation of actomyosin and the reassociation of Actin and myosin are accompanied by the breakdown and formation, respectively, of cross-bridges between the thick and thin filaments of myofibrils.



Last update: 06/08/2026

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