Separation and identification of Drosophila myosin light chains

Myosin was extracted from the larvae and adult flies of Drosophila melanogaster, and purified by column chromatography in the presence of KI. Myosin light chains were separated from heavy chains by column chromatography after treatment of the myosin with urea, and they were identified by 2D-gel electrophoresis. Tubular muscles and fibrillar muscles have different light chains. Lt1 (Mw = 31,000), Lt2 (Mw = 30,000), Lt2' (Mw = 30,000), and Lt3 (Mw = 20,000) exist in the tubular myosin of both larvae and adult flies; Lf1 (Mw = 34,000), Lf2 (Mw = 30,000), Lf2' (Mw = 30,000), and Lf3 (Mw = 20,000) exist in the fibrillar myosin. Polyacrylamide gel electrophoresis of myosin under nondissociating conditions revealed that there was one major myosin isozyme in each type of adult muscle, and the re-electrophoresis of each isozyme on SDS gel confirmed our identification of the light chains.