STUDIES ON THE CATALYTIC ACTIVITY OF HORSERADISH-PEROXIDASE HOSTED IN AEROSOL OT REVERSE MICELLES CONTAINING CHOLESTEROL

The addition of cholesterol into the AOT/isooctane/H2O system makes the surfactant monolayer of the reverse micellar droplets rigid with concomitant decrease of interdroplet interactions. So a peroxidase molecule hosted by some of these droplets experiences a completely different atmosphere than that without the additive. The change of composition of the reverse micelles results in enhancing the catalytic activity of the enzyme at various temperatures and pH values. A different trend of variation of molar absorption coefficient (epsilon) is also found till W(o) congruent-to 10, where epsilon gradually decreases with a rise in W(o) value till W(o) congruent-to 10 and above which it remains more or less constant. There is no shift of pH profile in the micellar system by the introduction of the cholesterol into it. By measuring the catalytic constant (k(cat)) it is found that the critical W(o) shifts from 12 to a value 10.