Activation of serine protease subtilisin Carlsberg in organic solvents: combined effect of methyl-beta-cyclodextrin and water

Methyl beta-cyclodextrin (M beta CD) increased the activity and enantiosele ctivity of lyophilized subtilisin suspended in dry THF and acetonitrile in two transesterification model reactions. These beneficial improvements were diminished by the addition of water, in contrast to the observation that w ater activates subtilisin lyophilized from buffer alone. For example, the i nitial rate for the S enantiomer in the transesterification of vinylbutyrat e with (+/-)-1-phenylethanol (sec-phenethylalcohol) decreased ca. 4-fold an d the enantioselectivity from 59 to 40 when 0.1% (v/v) of water was added t o THF.