Thermal Inactivation of Soybean Lipoxygenase and Its Secondary Structure Performance of Circular Dichroism Specctroscopy

The inactivation and secondary structure variation of soybean lipoxygenase(LOX) during heating process was studied with circular dichroism(CD) spectroscopy.The quantitative secondary structures of LOX at various temperatures were obtained.At 50～65 ℃,LOX activity has a sharp drop with the time prolonging.Thermal inactivation of LOX could be described by a first order kinetic model,and activation energy Ea was further calculated to be 217 kJ·mol-1.During the heating process,the contents of α-helix and β-sheet were both floating at 20%,indicated that the change of secondary structure of LOX was not the main reason for the loss of their activities.