Besides the cephalosporin acylase I activity which converts GL-7ACA into 7-ACA; this enzyme displays some gamma glutamyltranspeptidase activity. (7R)-7-(4-carboxybutanamido)cephalosporanate + H2O = (7R)-7-aminocephalosporanate + glutarate an alpha-amino acid + an N-terminal (5-L-glutamyl)-[peptide] = 5-L-glutamyl amino acid + N-terminal L-alpha-aminoacyl-[peptide] glutathione + H2O = L-cysteinylglycine + L-glutamate an S-substituted glutathione + H2O = an S-substituted L-cysteinylglycine + L-glutamate Dimer of two non-identical chains processed from the same precursor. Belongs to the gamma-glutamyltransferase family.