Glycosylation of the primary binding pocket of a subtilisin protease causes a remarkable broadening in stereospecificity in peptide synthesis

Abstract

Site-selective glycosylation at position 166 at the base of the primary specificity S1 pocket in the serine protease subtilisin Bacillus lentus (SBL) created glycoproteins that are capable of catalyzing the coupling reactions of not only L- amino acid esters but also D-amino acid esters to give the corresponding dipeptides in good yields as a result of greatly broadened substrate specificities that can be rationalized by the interaction of the glycans acting as chiral auxiliaries in stereochemically mismatched pairs.