Isolation and characterization of myosin light chains from skipjack ordinary muscle.

Abstract

A1, A2 and DTNB light chains were isolated from the ordinary muscle of skipjack Katsuwonus pelamis by a method consisting of DEAE-cellulose column chromatography and high-speed gelfiltration. Molecular weights were 30, 000, 22, 500 and 20, 000 for A1, A2 and DTNB light chain, respectively. The three light chains were rather acidic, with isoelectric points ranging from 4.7-4.8. All of them were rich in aspartic and glutamic acids, asanine and glycine, and poor in half cystine, tyrosine and histidine, as are light chains from other sources. Alcontained alanine at an especially high level, while DTNB light chain contained try ptophan exclusively. They all clearly showed absorption maxima at 253, 259, 265 and 269 nm, indicating abundunce of phenylalanine. It was concluded from these results that skipjack myosin light chains are compraable to those of other fishes so far reported, except for small but signifcant differences in chromatogrphic behavior, molecular size and amino acid composition.