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Cellular and Molecular Life Sciences :... Apr 1998The biosynthesis of peptidoglycan is a two-stage process. The first stage concerns the endocellular assembly of its monomer unit, whereas the second one concerns the... (Review)
Review
The biosynthesis of peptidoglycan is a two-stage process. The first stage concerns the endocellular assembly of its monomer unit, whereas the second one concerns the exocellular polymerization steps. The continued interest for this system is due to (i) the emergence of new resistance mechanisms; (ii) the need of specific targets in the search for new antibacterials; and (iii) the steady progress in the study of the correlation of peptidoglycan metabolism with cell growth and division. The various steps of the assembly of the monomer unit will be discussed as well as the correlations between the two stages. Finally, the flexibility of the pathway will be exemplified in Escherichia coli and Staphylococcus aureus.
Topics: Escherichia coli; Peptidoglycan; Staphylococcus aureus
PubMed: 9614964
DOI: 10.1007/s000180050155 -
FEMS Microbiology Reviews Mar 2008
Topics: Bacteria; Drug Resistance, Bacterial; Peptidoglycan
PubMed: 18291012
DOI: 10.1111/j.1574-6976.2008.00108.x -
Annual Review of Microbiology 2014Peptidoglycan serves as a key structure of the bacterial cell by determining cell shape and providing resistance to internal turgor pressure. However, in addition to... (Review)
Review
Peptidoglycan serves as a key structure of the bacterial cell by determining cell shape and providing resistance to internal turgor pressure. However, in addition to these essential and well-studied functions, bacterial signaling by peptidoglycan fragments, or muropeptides, has been demonstrated by recent work. Actively growing bacteria release muropeptides as a consequence of cell wall remodeling during elongation and division. Therefore, the presence of muropeptide synthesis is indicative of growth-promoting conditions and may serve as a broadly conserved signal for nongrowing cells to reinitiate growth. In addition, muropeptides serve as signals between bacteria and eukaryotic organisms during both pathogenic and symbiotic interactions. The increasingly appreciated role of the microbiota in metazoan organisms suggests that muropeptide signaling likely has important implications for homeostatic mammalian physiology.
Topics: Animals; Bacteria; Bacterial Infections; Humans; Peptidoglycan; Polysaccharides, Bacterial; Signal Transduction
PubMed: 24847956
DOI: 10.1146/annurev-micro-091213-112844 -
Journal of Bacteriology Apr 2009
Topics: Aliivibrio fischeri; Animals; Decapodiformes; Morphogenesis; Peptidoglycan
PubMed: 19151142
DOI: 10.1128/JB.01801-08 -
Journal of Visualized Experiments : JoVE Oct 2020Peptidoglycan is an important component of bacterial cell walls and a common cellular target for antimicrobials. Although aspects of peptidoglycan structure are fairly...
Peptidoglycan is an important component of bacterial cell walls and a common cellular target for antimicrobials. Although aspects of peptidoglycan structure are fairly conserved across all bacteria, there is also considerable variation between Gram-positives/negatives and between species. In addition, there are numerous known variations, modifications, or adaptations to the peptidoglycan that can occur within a bacterial species in response to growth phase and/or environmental stimuli. These variations produce a highly dynamic structure that is known to participate in many cellular functions, including growth/division, antibiotic resistance, and host defense avoidance. To understand the variation within peptidoglycan, the overall structure must be broken down into its constitutive parts (known as muropeptides) and assessed for overall cellular composition. Peptidoglycomics uses advanced mass spectrometry combined with high-powered bioinformatic data analysis to examine peptidoglycan composition in fine detail. The following protocol describes the purification of peptidoglycan from bacterial cultures, the acquisition of muropeptide intensity data through a liquid chromatograph-mass spectrometer, and the differential analysis of peptidoglycan composition using bioinformatics.
Topics: Cell Wall; Chromatography, High Pressure Liquid; Chromatography, Liquid; Computational Biology; Glycomics; Mass Spectrometry; Peptidoglycan
PubMed: 33135689
DOI: 10.3791/61799 -
Carbohydrate Polymers Sep 2015Lactobacillus species are potential probiotic bacteria for humans because of their capacity to improve certain biological functions in the host's immune system. In this...
Lactobacillus species are potential probiotic bacteria for humans because of their capacity to improve certain biological functions in the host's immune system. In this study, we focused on three peptidoglycans (PGNs) derived from different Lactobacillus strains and investigated each PGN's anti-inflammatory capacity. Each PGN was analyzed using HPLC, MALDI-TOF/TOF MS and FTIR. All three PGNs displayed a β-1,4-linked N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) structure with some modifications in the polypeptides at the end of the MurNAc residue. In a new insight, we found that PGNs inhibit the release of inflammatory cytokines in LPS-induced RAW 264.7 cells; a capacity that may be related to the TLR-4 pathway. The goal for exploring PGN diversity in Lactobacillus strains is to better understand the potential use of Lactobacillus PGNs in food and pharmaceutical applications.
Topics: Animals; Anti-Inflammatory Agents; Cell Line; Cytokines; HT29 Cells; Humans; Lactobacillus; Lipopolysaccharides; Mice; Peptidoglycan; Phagocytosis; Toll-Like Receptor 4
PubMed: 26005148
DOI: 10.1016/j.carbpol.2015.04.026 -
Methods in Enzymology 2022The bacterial cell wall, whose main component is peptidoglycan (PG), provides cellular rigidity and prevents lysis from osmotic pressure. Moreover, the cell wall is the...
The bacterial cell wall, whose main component is peptidoglycan (PG), provides cellular rigidity and prevents lysis from osmotic pressure. Moreover, the cell wall is the main interface between the external environment and internal cellular components. Given its essentiality, many antibiotics target enzymes related to the biosynthesis of cell wall. Of these enzymes, transpeptidases (TPs) are central to proper cell wall assembly and their inactivation is the mechanism of action of many antibiotics including β-lactams. TPs are responsible for stitching together strands of PG to make the crosslinked meshwork of the cell wall. This chapter focuses on the use of solid-phase peptide synthesis to build PG analogs that become site-selectively incorporated into the cell wall of live bacterial cells. This method allows for the design of fluorescent handles on PG probes that will enable the interrogation of substrate preferences of TPs (e.g., amidation at the glutamic acid residue, crossbridge presence) by analyzing the level of probe incorporation within the native cell wall of live bacterial cells.
Topics: Anti-Bacterial Agents; Bacteria; Cell Wall; Peptidoglycan
PubMed: 35379437
DOI: 10.1016/bs.mie.2021.11.019 -
Cell Reports May 2019In Drosophila, it is thought that peptidoglycan recognition proteins (PGRPs) SA and LC structurally discriminate between bacterial peptidoglycans with lysine (Lys) or...
In Drosophila, it is thought that peptidoglycan recognition proteins (PGRPs) SA and LC structurally discriminate between bacterial peptidoglycans with lysine (Lys) or diaminopimelic (DAP) acid, respectively, thus inducing differential antimicrobial transcription response. Here, we find that accessibility to PG at the cell wall plays a central role in immunity to infection. When wall teichoic acids (WTAs) are genetically removed from S. aureus (Lys type) and Bacillus subtilis (DAP type), thus increasing accessibility, the binding of both PGRPs to either bacterium is increased. PGRP-SA and -LC double mutant flies are more susceptible to infection with both WTA-less bacteria. In addition, WTA-less bacteria grow better in PGRP-SA/-LC double mutant flies. Finally, infection with WTA-less bacteria abolishes any differential activation of downstream antimicrobial transcription. Our results indicate that accessibility to cell wall PG is a major factor in PGRP-mediated immunity and may be the cause for discrimination between classes of pathogens.
Topics: Animals; Antimicrobial Cationic Peptides; Bacillus subtilis; Carrier Proteins; Cell Wall; Drosophila; Drosophila Proteins; Immunity, Innate; Mutagenesis; Peptidoglycan; Protein Binding; Recombinant Proteins; Staphylococcus aureus; Teichoic Acids; Transcriptional Activation
PubMed: 31116990
DOI: 10.1016/j.celrep.2019.04.103 -
Glycobiology Mar 2001The main structural features of bacterial peptidoglycan are linear glycan chains interlinked by short peptides. The glycan chains are composed of alternating units of... (Review)
Review
The main structural features of bacterial peptidoglycan are linear glycan chains interlinked by short peptides. The glycan chains are composed of alternating units of N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc), all linkages between sugars being beta,1-->4. On the outside of the cytoplasmic membrane, two types of activities are involved in the polymerization of the peptidoglycan monomer unit: glycosyltransferases that catalyze the formation of the linear glycan chains and transpeptidases that catalyze the formation of the peptide cross-bridges. Contrary to the transpeptidation step, for which there is an abundant literature that has been regularly reviewed, the transglycosylation step has been studied to a far lesser extent. The aim of the present review is to summarize and evaluate the molecular and cellullar data concerning the formation of the glycan chains in the synthesis of peptidoglycan. Early work concerned the use of various in vivo and in vitro systems for the study of the polymerization steps, the attachment of newly made material to preexisting peptidoglycan, and the mechanism of action of antibiotics. The synthesis of the glycan chains is catalyzed by the N-terminal glycosyltransferase module of class A high-molecular-mass penicillin-binding proteins and by nonpenicillin-binding monofunctional glycosyltransferases. The multiplicity of these activities in a given organism presumably reflects a variety of in vivo functions. The topological localization of the incorporation of nascent peptidoglycan into the cell wall has revealed that bacteria have at least two peptidoglycan-synthesizing systems: one for septation, the other one for elongation or cell wall thickening. Owing to its location on the outside of the cytoplasmic membrane and its specificity, the transglycosylation step is an interesting target for antibacterials. Glycopeptides and moenomycins are the best studied antibiotics known to interfere with this step. Their mode of action and structure-activity relationships have been extensively studied. Attempts to synthesize other specific transglycosylation inhibitors have recently been made.
Topics: Bacteria; Biopolymers; Cell Wall; Enzyme Inhibitors; Glycosylation; Glycosyltransferases; Peptidoglycan; Protoplasts
PubMed: 11320055
DOI: 10.1093/glycob/11.3.25r -
Methods in Molecular Biology (Clifton,... 2017Bacteria have developed a number of trans-envelope systems to transport molecules or assemble organelles across bacterial envelopes. However, bacterial envelopes contain...
Bacteria have developed a number of trans-envelope systems to transport molecules or assemble organelles across bacterial envelopes. However, bacterial envelopes contain a rigid netlike peptidoglycan structure that protects cells from osmotic lysis. Trans-envelope systems thus must interact with the peptidoglycan barrier to generate gaps or anchor structures to the peptidoglycan scaffold. Here we describe methods to use in vivo cross-linking and in vitro co-sedimentation to study protein-peptidoglycan interactions in Gram-negative bacteria. In particular, we address important considerations to ensure the specificity of the interactions in question.
Topics: Bacterial Proteins; Electrophoresis, Polyacrylamide Gel; Gram-Negative Bacteria; Membrane Proteins; Peptidoglycan; Protein Binding
PubMed: 28667609
DOI: 10.1007/978-1-4939-7033-9_11