Related Experiment Videos
Tropomyosin inhibits the rate of actin polymerization by stabilizing actin filaments
S E Hitchcock-DeGregori1, P Sampath, T D Pollard
1Department of Anatomy, UMDNJ-Robert Wood Johnson Medical School, Piscataway 08854.
Biochemistry
|December 27, 1988
Abstract:
Tropomyosin inhibition of the rate of spontaneous polymerization of actin is associated with binding of tropomyosin to actin filaments. Rate constants determined by using a direct electron microscopic assay of elongation showed that alpha alpha- and alpha beta-tropomyosin have a small or no effect on the rate of elongation at either end of the filaments. The most likely explanation for the inhibition of the rate of polymerization of actin in bulk samples is that tropomyosin reduces the number of filament ends by mechanical stabilization of the filaments.