EFFECT OF SUPPORT MATERIAL AND ENZYME PRETREATMENT ON ENANTIOSELECTIVITY OF IMMOBILIZED SUBTILISIN IN ORGANIC-SOLVENTS

Subtilisin Carlsberg was covalently attached to five macroporous acryl ic supports of varying aquaphilicity (a measure of hydrophilicity). Ki netic parameters of the transesterification of S and R enantiomers of secphenethyl alcohol with vinyl butyrate, catalyzed by various immobil ized subtilisins, were determined in anhydrous dioxane and acetonitril e. Enzyme enantioselectivity in acetonitrile, but not in dioxane, corr elated with the aquaphilicity of the support; a mechanistic rationale for this phenomenon was proposed. Although the catalytic activity of i mmobilized subtilisin in anhydrous solvents strongly depended on enzym e pretreatment, the enantioselectivity was essential conserved. (C) 19 94 John Wiley and Sons, Inc.