Disulfide bonds influence the heat-induced gel properties of chicken breast muscle myosin

The functions of thiol groups in the denaturation, aggregation and gelation of chicken breast muscle myosin during heating in 0.6M NaCl, 50mM sodium phosphate buffer, pH 6.5, was investigated by inhibiting disulfide (SS) bond formation using dithiothreitol (DTT). The endotherm of myosin heated in the presence or absence of DTT had similar thermal transition temperatures. Preventing SS bond formation increased the onset temperature for aggregation and gelation and decreased the elastic-like properties of the final gel matrix. Results indicated that SS bond formation was not a prerequisite for the gelation of chicken breast myosin. However, intermolecular SS bonds, especially from thiol groups on subfragment-1, contributed to gel network formation.