Small subunits in myosin

An attempt has been made to depolymerize myosin by increasing its negative charge through acetylation and carboxymethylation. A study of the fractions obtained by chromatography of the products on DEAE-cellulose showed that while the main structure of the molecule apparently remained intact, both types of substitution dissociated at least 15% of small subunits, even from highly purified myosin. These were separated by preparative gel electrophoresis and were found to consist of 3 components in comparable amounts, with molecular weights of 17,000, 19,000, and 20,000. The presence of two of these in acetylated H-meromyosin and not in L-meromyosin indicates a location in the head of the myosin molecule.