Open AccessBacterial‐Cell‐Wall Peptidoglycan Fragments Produced by Phage λ or Vi II Endolysin and Containing 1,6‐Anhydro‐ N ‐acetylmuramic Acid
Author(s) -
TAYLOR Alina,
DAS Bhupesh C.,
HEIJENOORT Jean
Publication year - 1975
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1975.tb04040.x
Subject(s) - peptidoglycan , lysin , biochemistry , cell wall , glycan , bacteriophage , peptide , chemistry , hydrolysis , lysis , diaminopimelic acid , bacterial cell structure , amino acid , escherichia coli , biology , bacteria , glycoprotein , gene , genetics
The cell wall peptidoglycan of Escherichia coli or Salmonella typhi were hydrolysed to dialysable non‐reducing fragments by partially purified preparations of the bacteriolytic activity present in lysates of phage λ or Vi II. The structure of the two main fragments resulting from this digestion was determined In each case the lack of reducing power is explained by the presence of a 1,6‐anhydro‐ N ‐acetylmuramic acid residure at what should normally be the reducing end of the peptidoglycan fragment. Furthermore, no d ‐alanyl‐( d )‐ meso ‐diaminopimelyl peptide crosslinkages were detected in these fragments. These results indicate that the partially purified preparations of phage λ or phage Vi II endolysin contain at least two different types of hydrolytic activities: a phage endopeptidase responsible for the cleavage of the peptide crosslinkages present in peptidoglycan and a new type of N ‐acetylmuramidase activity which not only cleaves β‐1 → 4 linkages between N ‐acetylmuramic acid and N ‐acetylglucosamine residues in the glycan moiety of peptidoglycan, but also catalyses a dehydration with the formation of 1, 6‐anhydro‐ N ‐acetylmuramic acid residues.