Activity and stability of Bacillus cereus penicillinase entrapped in aerosol OT reverse micelles

The kinetics of enzyme catalyzed hydrolysis of penicillin G and stability of the enzyme alpha-penicillinase, entrapped in aerosol OT reverse micellar droplets have been investigated spectrophotometrically. Various physical parameters, such as, water pool size (related to Wo), pH and temperature, were optimized for maximum activity of penicillinase in water/aerosol OT/isooctane reverse micelles. The enzyme showed maximum activity of Wo - 14 and pH, 7.0. At any temperature the enzyme was to be more active in reverse micelles than in aqueous solution. At optimum conditions of Wo, pH and temperature the enzyme was 100% more active in reverse micelles than its maximum activity in aqueous solution. In both the systems, the activity starts falling at and above 25 degrees C. CD Spectral studies showed that the enzyme in reverse micelles possesses more helical structure than it has in aqueous solution and at the optimum conditions in which it showed maximum activity, the alpha-helicity was also maximum. The enzyme was very stable in reverse micelles at and above room temperature compared to the same in aqueous solution.