Al, 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 gel filtration. Molecular weights were 30,000, 22,500 and 20,000 for Al, 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, alanine and glycine, and poor in half cystine, tyrosine and histidine, as are light chains from other sources. Al contained alanine at an especially high level, while DTNB light chain contained tryptophan 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 comparable to those of other fishes so far reported, except for small but significant differences in chromatographic behavior, molecular size and amino acid composition.
ASJC Scopus subject areas
- Aquatic Science