The Exchange Reaction of Peptides R-d-Alanyl-d-alanine with d-[14C]Alanine to R-d-Alanyl-d-[14C]alanine and d-Alanine, Catalysed by the Membranes of Streptococcus faecalis ATCC 9790

Abstract
Under alkaline conditions, the membrane-bound DD-carboxypeptidase [EC 3.4.12.6] of S. faecalis ATCC 9790 catalyzes exchange reactions in which the X-L-R3-D-Ala moiety of peptides of the type X-L-R3-D-Ala-D-Ala is transferred to simple amino compounds such as D-alanine, glycine and glycyl-glycine. The enzyme system is unable to catalyze complex reactions that would simulate the natural transpeptidation reaction.