| abstract |
A method for transamidating a peptide substrate having a P1 amino acid residue with a positively charged side chain. According to the invention, carboxypeptidase Y is modified to substitute at least one amino acid having a negatively charged side chain in an S1 subsite. Additionally, the modified carboxypeptidase Y can include substituted amino acid residues in an S1', S2 and/or S3 subsite to accommodate a specific peptide substrate. |