Abstract: The mechanism of heat-induced gelation of myosin was investigated by studying physico-chemical changes of rabbit myosin during at pH 6.5, high ionic strength of 0.6mol/L KCl. A slight decrease in α-helical content was observed at 25 ℃, then a rapid decrease from 43 to 65 ℃, followed by a plateau after 65 ℃. Turbidity increased at 40 ℃ which indicated the beginning of the aggregation, remaining constantly after 65 ℃. Reactive sulfhydryl content increased from 40 ℃, reaching a maximum at 65 ℃. Total sulphydryl content decreased from 30 ℃. Surface hydrophobicity increased non-linearly between 30～85 ℃. G’ increased slowly between 48 and 71 ℃, sharply from 71 to 82 ℃. It was concluded that denaturation of myosin was initialized by unfolding of the α-helical and followed by the exposure of sulphydryl and hydrophobic residues. Disulfide linkages, hydrophobic interactions and hydrogen bonds could enhance the elasticity of the gelation of myosin together.

Key words: myosin, gelation, physico-chemical characteristics