Peptidoglycan structure of Lactobacillus casei, a species highly resistant to glycopeptide antibiotics.
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.
Billot-Klein
D
D
L.R.M.A., Université Paris VI, France.
Legrand
R
R
Schoot
B
B
van Heijenoort
J
J
Gutmann
L
L
D000107:Acetylation; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004352:Drug Resistance, Microbial; D007780:Lacticaseibacillus casei / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D013058:Mass Spectrometry; D008970:Molecular Weight; D009842:Oligopeptides / Q000737:chemistry / Q000302:isolation & purification; D010400:Penicillin G / Q000494:pharmacology; D010457:Peptidoglycan / Q000737:chemistry* / Q000378:metabolism
D000900:Anti-Bacterial Agents; D009842:Oligopeptides; D010457:Peptidoglycan; D010400:Penicillin G