Yoji Suzuyama

The L-2 light chain of chicken skeletal muscle myosin.

As with rabbit skeletal muscle myosin, four kinds of light chains may be separated from chicken skeletal muscle myosin by cellogel electrophoresis at pH 8.3. They are designated L-l, L-2, L-3 and L-4 in the order of their increasing anionic mobilities. L-1 is also known as alkali light chain 1 (A1) and L-4 as alkali light chain 2 (A2). L-2 and L-3 are also called DTNB light chain. L-3 is a phosphorylated L-2 light chain. Interest in the role of these myosin light chains in the mechanism of muscle contraction has been marked. The primary structures of L-1 and L-4 light chains of rabbit skeletal muscle myosin have been determined by Frank and Weeds [1] ; they contain 190 and 149 amino acids, respectively. The primary structure of the L-2 light chain of rabbit skeletal muscle myosin has been determined by Collins [2] and by Matsuda et al. [3]. The amino acid composition of the L-2 light chain of chicken skeletal muscle myosin has been found by Lowey and Holt [4] and its partial amino acid sequence reported by Jakes et al. [5]. We report here the primary structure of the L-2 light chain of chicken skeletal muscle myosin.

The amino acid compositions of the tryptic, chymotryptic and peptic peptides from the L-2 light chain of rabbit skeletal muscle myosin.

The light chain fraction was separated from rabbit skeletal muscle myosin and four kinds of light chains, L-1, L-2, L-3 and L-4 in the fraction were further isolated by column chromatography using DEAE-cellulose DE-52. After amino-ethylation, the L-2 light chain was digested with trypsin. It was also digested with chymotrypsin and pepsin, respectively, after carboxymethylation. Each of the tryptic, chymotryptic and peptic peptides thus obtained was separated and purified and their amino acid compositions were analyzed.