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-γ-Glu-Lys-d-Ala-Ala-Ala. The only glycosidase activity present is that of N-acetyl-β-d-muramidase.