Effect of Buffers on the Polymerization of Protein through Disulfide Bonding during Heating of Myosin from Carp Muscle

Myosin from carp muscle was heated at 80°C in 0.6M NaCl solutions containing various kinds of buffer (pH 6.8), and the polymerization behavior of proteins through SS bonding (SS polymerization) was analyzed by SDS-polyacrylamide gel electrophoresis. In the phosphate buffer and Tris-HCl buffer, the oxidation of SH groups in myosin and SS polymerization of myosin heavy chain were promoted, which suggested that metal ions from the reagents used might be related to them. In Tris-maleate buffer and Tris-maleic anhydride buffer, the content of SH groups decreased more than in the phosphate buffer and in Tris-HCl buffer, but the decrease was not inhibited by a metal chelating reagent (EDTA) Moreover, in Tris-maleate buffer, SS polymerization was inhibited, and in Tris-maleic anhydride buffer, SS polymerization through covalent bonding other than SS bonding occurred. Therefore, it was concluded that these two buffers are not suitable for the research of SS polymerization.