Crown ether activation of cross-linked subtilisin Carlsberg crystals in organic solvents

The activity of cross-linked subtilisin Carlsberg crystals in the catalysis of peptide bond formation can be significantly enhanced by pretreatment of the enzyme crystals with crown ethers. Soaking of the enzyme crystals in a solution of crown ether in acetonitrile followed by evaporation of the solvent results in an up to 13 times enhanced enzymatic activity. The effects of crown ether treatment under various conditions gives support for the hypothesis that removal of bound water molecules from the active site during the drying process is the origin of the observed enzyme activation.