Dynamic viscoelastic study of the effect of beta-actinin on the interaction between F-actin and heavy meromyosin.
Beta-Actinin, a regulatory protein of muscle, greatly decreased the dynamic rigidity modulus of an acto-heavy meromyosin solution. However, it was found that the mechanical mixing procedure used resulted in fragmentation of the decorated F-actin particles and beta-actinin inhibited the reassociation of the fragmented particles. This was the reason for the decrease of the dynamic rigidity modulus of the acto-heavy meromyosin complex caused by beta-actinin. When beta-actinin was added to the acto-heavy meromyosin solution in the presence of ATP, it did not affect the visco-elasticity. F-actin particles dissociated by ATP were not fragmented by the mixing procedure, which was responsible for the apparent inactivation of beta-actinin in the presence of ATP.
D000199:Actins; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001718:Birefringence; D004548:Elasticity; D007700:Kinetics; D009124:Muscle Proteins / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism; D015879:Myosin Subfragments; D011487:Protein Conformation; D011817:Rabbits; D013997:Time Factors; D014783:Viscosity
D000199:Actins; D009124:Muscle Proteins; D015879:Myosin Subfragments; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases