Open AccessPeptidoglycan structure of Lactobacillus casei, a species highly resistant to glycopeptide antibiotics
Author(s) -
D Billot-Klein,
Raymond Legrand,
Bernard Schoot,
Jean van Heijenoort,
Laurent Gutmann
Publication year - 1997
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.179.19.6208-6212.1997
Subject(s) - lactobacillus casei , peptidoglycan , biology , tetrapeptide , penicillin , biochemistry , glycopeptide , microbiology and biotechnology , lactobacillus , antibiotics , carboxypeptidase , cell wall , peptide , enzyme , fermentation
The structure of the peptidoglycan of Lactobacillus casei ATCC 393, a species highly resistant to glycopeptide antibiotics, was examined. After digestion, 23 muropeptides were identified; monomers represented 44.7% of all muropeptides, with monomer tetrapeptides being the major ones. Fifty-nine percent of the peptidoglycan was O-acetylated. The cross-bridge between D-alanine and L-lysine consisted of one asparagine, although aspartate could be found in minor quantities. Since UDP-MurNAc-tetrapeptide-D-lactate is the normal cytoplasmic precursor found in this species, monomer tetrapeptide-lactate was expected to be found. However, such a monomer was found only after exposure to penicillin, suggesting that penicillin-sensitive D,D-carboxypeptidases were very active in normal growing cells.