Pressure affects enzyme function in organic media

Pressure affects enzyme function in nonaqueous media. Activation volumes have been determined and provide evidence that the primary effect of pressure is to enhance the stripping of water off an enzyme in polar organic solvents and leads to decreased enzymatic activity. Activation volumes of subtilisin Carlsberg in organic solvents, particularly with the enzyme hydrated, have a larger magnitude than activation volumes determined in aqueous solutions. This study provides further evidence that enzymatic activity in polar organic solvents is dominated by the interaction of enzyme-bound water with the solvent. From a practical standpoint, however, the results of this study suggest that enzymatic catalysis in organic solvents may be controlled by the combined effects of pressure and enzyme hydration. (c) 1993 John Wiley & Sons, Inc.