title: Effect of cytochalasin B on formation and properties of muscle F-actin.
abstract: Cytochalasin B stimulated polymerization and decreased the concentration of G-actin remaining in equilibrium with F-actin filaments. Polymerization in the presence of cytochalasin B gave rise to a smaller increase of viscosity but to the same increase in light scattering, compared to polymerization in the absence of cytochalasin B. Cytochalasin B reduced the viscosity of F-actin and caused the appearance of ATP hydrolysis by F-actin. The cytochalasin B-induced ATPase activity was inhibited by concentrations of KCl higher than 50 mM. The cytochalasin B-induced ATPase activity was enhanced by ethyleneglycol bis(alpha-aminoethyl ether)-N,N'-tetraacetic acid and reduced by MgCl2 at concentrations higher than 0.75 mM. The findings suggest that the stability of actin filaments is reduced by cytochalasin B.
mesh_terms: D000199:Actins / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D003571:Cytochalasin B / Q000494:pharmacology*; D004533:Egtazic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D007700:Kinetics; D046911:Macromolecular Substances; D008274:Magnesium / Q000494:pharmacology; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D011485:Protein Binding; D014783:Viscosity
chemical_list: D000199:Actins; D046911:Macromolecular Substances; D003571:Cytochalasin B; D004533:Egtazic Acid; D011189:Potassium Chloride; D000251:Adenosine Triphosphatases; D008274:Magnesium