Studies on Amino Acid Sequences of Two Isoforms of 17-kDa Essential Light Chain of Smooth Muscle Myosin from Porcine Aorta Media

Abstract

Amino acid sequences were analyzed for two isoforms of myosin essential light chain, LC17a and LC17b [Hasegawa, Y., Ueno, H., Horie, K., & Morita, F. (1988) J. Biochem. 103, 15-18] from porcine aorta smooth muscle. Both LC17a and LC17b consisted of 150 amino acid residues and their N-terminal Cys residues were blocked by an acetyl group. The amino acid sequences of LC17a and LC17b were common from the N-terminal to Glu-141 and five amino acid substitutions were observed within the remaining C-terminal 9 residues. The amino acid sequences of LC17a and LC17b were identical to those deduced from the nucleotide sequences of bovine aortic cDNAs encoding the two isoforms [Lash, J. A., Helper, D. J., Klug, M., Nicolozakes, A. W., & Hathaway, D. R. (1990) Nucleic Acids Res. 18, 7176].