The role of sarcoplasmic protein in hydrostatic pressure-induced myofibrillar protein denaturation

To observe the role of sarcoplasmic protein (SP) on myofibrillar protein (MP) denaturation under a hydrostatic pressure (HP), MP isolated from bovine muscle was treated with 300 MPa by increasing concentrations of SP (0, 0.8, 1.6, and 3.2 mg/ml) from bovine. SDS-PAGE patterns of soluble proteins in 0.1 M NaCl (pH 7.4) indicated that a protein (about 100 kDa) from MP decreased with increasing concentrations of SP and that a 97 kDa protein from SP observed with 0.1 MPa was not observed with 300 MPa. SDS-PAGE patterns of soluble proteins in 0.6 M NaCl (pH 7.4) and Ca-ATPase activity showed that the denaturation of myosin heavy chain (MHC) was accelerated with increasing SP concentrations with the 300 MPa treatment. Thus, the addition of SP enhanced HP-induced denaturation of MHC and of a protein from MP of about 100 kDa.