Classification of tropomyosin components into an α-like or a β-like family by partial peptide mapping

Abstract

Tropomyosins can be classified as belonging to an α-like or a β-like family depending on the absence or presence, respectively, in their protease-V8 digestion pattern of two peptides with an apparent molecular mass of 21 kDa. Chicken cardiac tropomyosin and the 43 kDa component from gizzard tropomyosin are accordingly classified as α-like tropomyosins, while the 33 kDa gizzard tropomyosin component is a β-like tropomyosin. The 21 kDa peptides have an overall charge which is more positive than that of the intact tropomyosin or any other tropomyosin peptide and probably contain the -NH 2 half of the molecule.