Endopeptidase and glycosidase activities of the bacteriophage B30 lysin.

Synthetic peptides corresponding to portions of group B streptococcal peptidoglycan were used to show that the endopeptidase activity of bacteriophage B30 lysin cleaves between D-Ala in the stem peptide and L-Ala in the cross bridge and that the minimal peptide sequence cleaved is DL-gamma-Glu-Lys-D-Ala-Ala-Ala. The only glycosidase activity present is that of N-acetyl-beta-D-muramidase.