Properties of amino acid composition of the tryptic fragments of the heavy chain of myosin subfragment-1.

Limited tryptic digestion of the heavy chain of chymotryptic myosin subfragment-1 gives three major fragments with approximate molecular weights of 50 K, 27 K, and 20 K daltons. We previously reported (Hozumi, T. & Muhlrad, A. (1981) Biochemistry 20, 2945-2950) that these fragments can be separated by gel filtration in 1% sodium dodecyl sulfate. By using this method, the tryptophan content and amino acid composition of fragments were measured. The 27 K and 50 K fragments were found to be rich in tryptophan, in contrast to the 20 K fragment.