LOW-MOLECULAR-WEIGHT SUBSTRATE FOR THE LYSOZYME OF T4-BACTERIOPHAGE

It has been shown that muropeptide CB, the chemically defined product of Escherichia coli B murein digestion by phage λ endolysin, is the substrate for T4 lysozyme. This is the tetrasaccharide GlcNAc‐MurNAc‐GlcNAc‐anMurNAc in which the carboxyl groups of MurNAc and anMurNAc residues are substituted by tetrapeptide lAla‐dGlu‐msA2pm‐dAla (MurNAc =N‐acetylmuramic acid, GlcNAc =N‐acetyl‐d‐glucosamine, anMurNAc = 1,6‐anhydro‐N‐acetylmuramic acid, lAla =l‐alanine, dClu =d‐glutamic acid, msA2pm =meso‐diaminopimelic acid). The substrate contains one bond hydrolysable by T4 lysozyme. The products of hydrolysis are the easily identifiable disaccharide muropeptides C6 (GlcNAc‐MurNAc‐lAla‐dGlu‐msA2pm‐dAla) and CA (GlcNAc‐anMurNac‐lAla‐dGlu‐msA2pm‐dAla). Thus the substrate may be used for the specific identification of murein N‐acetylmuramoylhydrolases of the T4 lysozyme type, as well as for any quantitative measurement of the enzymatic reaction. Copyright © 1979, Wiley Blackwell. All rights reserved