Subtilopeptidase A produced by Bacillus subtilis PR-70. II. Kinetic behaviour of immobilized enzyme

The kinetic behaviour of immobilized subtilopeptidase A was investigated. The enzyme was obtained from a local isolate of B. subtilis PR-70. Using different inorganic supports, Amberlite CG-50 was superior in this respect. It gave 97.8% adsorption, followed by silica gel GC. The values of K and K2 for the rate of enzyme catalyzed being 8.75 and 2.06, respectively. The behaviour of v against Et is the same as v against St. Michaelis' constant was determined using different methods. The average of Km value and Vmax were 0.0094 and 0.95, respectively. Studying how v behaves when St is varied while Et is constant, two active site per enzyme molecule and auto-inhibition of enzyme by its own substrate were observed. Comparing kinetic parameters of a soluble and insoluble subtilopeptidase A showed that Km decreased from 0.016 to 0.0094, while Vmax increased from 0.71 to 0.95, respectively. This indicated that when subtilopeptidase was bound to Amb. GC-50, a case of partially non-competitive inhibition occurred. The recovery of enzymatic activity in the water insoluble subtilopeptidase A is 12.8 per cent.