CATALYTIC AND REDOX REACTIONS OF PROTEINS AND LOW-MOLECULAR-WEIGHT REACTANTS IN REVERSE MICELLES

Analysis of the spectral characteristics of cytochrome c and the kinetics of its reduction by ascorbate in reverse micelles of aerosol OT and cetyltrimethylammonium bromide (CTAB) shows that the microenvironment of a micelle can exert a significant influence upon the structure and conformational dynamics of the protein and consequently upon the kinetic mechanism of its reactions. The rate constants for the reactions in the micellar phase have been estimated and the reasons for their deviation from those observed in aqueous solution established. Through the use of fast radical reactions, rate constants have been determined for the transfer of reactants between micelles of different surfactants, e.g. aerosol OT, sodium dodecylsulphate and cetylpyridinium chloride. It has been shown that the rate constants of ferrocytochrome c oxidation with peroxide catalyzed by peroxidase in reverse micelles of GTAB are weakly dependent upon the water content and are close to those in aqueous solution. A change in the microenvironment of the reactants upon their entrapment in CTAB reverse micelles provokes substantial changes in the equilibrium constants of the redox reactions.