Actin was found to be the major source of myofibrillar protein heterogeneity in smooth
muscles. Three isoelectric variants, alpha-smooth muscle (alpha-SM), beta-non-muscle
(beta-NM), and gamma-actins (gamma-SM and gamma-NM) were measured in 15 different
smooth muscles, alpha-SM and gamma-actin contents displayed an inverse relationship in a
given smooth muscle, some of which contained primarily alpha-SM actin while gamma-
actins dominated in others. alpha-SM actin and gamma-actin distributions were tissue …