Study on thermal stability and thermal inactivation kinetics of immobilized earthworm fibrinolytic enzyme

The thermal stability of immobilized and free enzyme were investigated by determining enzyme activity at different temperatures by fibrin plate method, and the thermal inactivation kinetic of immobilized and free earthworm fibrinolytic enzyme was analyzed. The results showed that the relative activity of immobilized and free earthworm fibrinolytic enzyme was gradually decreased and the rate of enzymes rapidly was inactivated with the increasing of temperature, both the activity of free and immobilized enzyme were decreased seriously when the temprature was up to 60 ℃, but the latter showed better thermal stability.Enzymatic kinetics analysis indicated that the apparent activation energy of immobilized and free earthworm fibrinolytic enzyme were 130.43 k J·mol- 1and116.65 k J·mol- 1respectively between 30 ℃ and 60 ℃。