Establishment of determination method of urease in soybean juice and the enzymology characteristics

The determination of trypsin inhibitor in the laboratory was very difficult,but the activity of urease was positively correlated with trypsin inhibitor concentration.Therefore,we established the measuring method for urease activity,and then the enzymology characteristics were studied.Results showed that the optimal values for urease activity as follows:detection wavelength 415nm,amount of nessler reagents 1mL,urea concentration 3%,reaction temperature 35℃,reaction time 7min.Meanwhile,the optimum reaction pH and temperature of soybean urease was 7.0 and 35℃,respectively.Incubation at 25～40℃for 3h,the retention rate of enzyme activity was above 80%.The Km and Vmax of urease were 0.173mmol/min and 0.0172mol/L,respectively.