The structure of secondary cell wall polymers: how Gram-positive bacteria stick their cell walls together

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 643-651 ◽  
Author(s):  
Christina Schäffer ◽  
Paul Messner
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Secondary Cell Wall ◽  
Chemical Study ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Bacterial Cell Surface ◽  
Cell Wall Polymers ◽  
Structural Principles

The cell wall of Gram-positive bacteria has been a subject of detailed chemical study over the past five decades. Outside the cytoplasmic membrane of these organisms the fundamental polymer is peptidoglycan (PG), which is responsible for the maintenance of cell shape and osmotic stability. In addition, typical essential cell wall polymers such as teichoic or teichuronic acids are linked to some of the peptidoglycan chains. In this review these compounds are considered as ‘classical’ cell wall polymers. In the course of recent investigations of bacterial cell surface layers (S-layers) a different class of ‘non-classical’ secondary cell wall polymers (SCWPs) has been identified, which is involved in anchoring of S-layers to the bacterial cell surface. Comparative analyses have shown considerable differences in chemical composition, overall structure and charge behaviour of these SCWPs. This review discusses the progress that has been made in understanding the structural principles of SCWPs, which may have useful applications in S-layer-based ‘supramolecular construction kits' in nanobiotechnology.

scholarly journals Revised mechanism of d-alanine incorporation into cell wall polymers in Gram-positive bacteria

Microbiology ◽  
2013 ◽  
Vol 159 (Pt_9) ◽  
pp. 1868-1877 ◽  
Author(s):  
Nathalie T. Reichmann ◽  
Carolina Picarra Cassona ◽  
Angelika Gründling
Keyword(s):  
Cell Wall ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Cell Wall Polymers

scholarly journals Modifications of cell wall polymers in Gram-positive bacteria by multi-component transmembrane glycosylation systems

2021 ◽  
Vol 60 ◽  
pp. 24-33
Author(s):  
Jeanine Rismondo ◽  
Annika Gillis ◽  
Angelika Gründling
Keyword(s):  
Cell Wall ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Cell Wall Polymers

Anchorage and release of Gram-positive bacterial cell-surface polypeptides

1995 ◽  
Vol 3 (9) ◽  
pp. 333-335 ◽  
Author(s):  
Howard F. Jenkinson
Keyword(s):  
Cell Surface ◽  
Bacterial Cell ◽  
Gram Positive ◽  
Bacterial Cell Surface

Infectious disease

2019 ◽  
Author(s):  
Stevan R. Emmett ◽  
Nicola Hill ◽  
Federico Dajas-Bailador
Keyword(s):  
Cell Wall ◽  
Protein Synthesis ◽  
Nucleic Acid ◽  
Outer Membrane ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Antibiotics include an extensive range of agents able to kill or prevent reproduction of bacteria in the body, without being overly toxic to the patient. Traditionally derived from living organisms, most are now chemically synthesized and act to disrupt the integrity of the bacterial cell wall, or penetrate the cell and disrupt protein synthesis or nucleic acid replication. Typically, bacteria are identified according to their ap­pearance under the microscope depending on shape and response to the Gram stain test. Further identification is obtained by growth characteristics on various types of culture media, based on broth or agar, biochemical and immunological profiles. Further testing on broth or agar determines antibiotic sensitivity to guide on anti­biotic therapy in individual patients. This process can take 24– 48 hours to culture and a further 24– 48 hours to measure sensitivities. Increasingly, new technology, e.g. Matrix Assisted Laser Desorption Ionization— Time of Flight (MALDI- TOF) and nucleic acid amplification as­says, are being used to provide more rapid identification. The Gram classification, however, is still widely referred to as it differentiates bacteria by the presence or absence of the outer lipid membrane (see Figure 11.1), a fundamental characteristic that influences antibiotic management. Antimicrobial agents rely on selective action exploiting genetic differences between bacterial and eukaryotic cells. They target bacterial cell wall synthesis, bacterial protein synthesis, microbial DNA or RNA synthesis, by acting on bacterial cell metabolic pathways or by inhibiting the ac­tion of a bacterial toxin (see Table 11.1). Both Gram- positive and Gram- negative bacteria possess a rigid cell wall able to protect the bacteria from varying osmotic pressures (Figure 11.1). Peptidoglycan gives the cell wall its rigidity and is composed of a glycan chain of complex alternating carbohydrates, N- acetylglucosamide (N- ATG), and N- acetylmurcarinic acid (N- ATM), that are cross- linked by peptide (or glycine) chains. In Gram-positive bacteria, the cell wall contains multiple peptido­glycan layers, interspersed with teichoic acids, whereas Gram- negative bacteria contain only one or two peptido­glycan layers that are surrounded by an outer membrane attached by lipoproteins. The outer membrane contains porins (which regulate transport of substances into and out of the cell), lipopolysaccharides, and outer proteins in a phospholipid bilayer. For both Gram- negative and Gram-positive bacteria, peptidoglycan synthesis involves about 30 bacterial enzymes acting over three stages. Since the cell wall is unique to bacteria, it makes a suitable target for antibiotic therapy.

Detection of bacterial cell wall hydrolases after denaturing polyacrylamide gel electrophoresis

1989 ◽  
Vol 35 (8) ◽  
pp. 749-753 ◽  
Author(s):  
Denis Leclerc ◽  
Alain Asselin
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Gel Electrophoresis ◽  
Cell Walls ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Cell Wall Hydrolases

Cell walls from various Gram-positive bacteria were incorporated at a concentration of 0.2% (w/v) into polyacrylamide gels as a substrate for detection of cell wall hydrolases. Bacterial extracts from crude cell wall preparations were denatured with sodium dodecyl sulfate and 2-mercaptoethanol and subjected to denaturing polyacrylamide gel electrophoresis in gels containing bacterial cell walls. After renaturation in the presence of purified and buffered 1% (v/v) Triton X-100, cell wall hydrolases were visualized as clear lytic zones against the opaque cell wall background. One to fifteen bands with lytic activity could be detected, depending on bacterial extracts and on the nature of the cell walls incorporated into gels. Crude cell wall extracts were the best source of cell wall hydrolases from various Gram-positive bacteria such as Clostridium perfringens (15 bands), Micrococcus luteus (1 band), Bacillus megaterium (4 bands), Bacillus sp. (6 bands), B. cereus (3 bands), B. subtilis (7 bands), Staphylococcus aureus (13 bands), Streptococcus faecalis (3 bands), and Strep. pyogenes (5 bands). Molecular masses of cell wall hydrolases ranged from 17 to 114.6 kDa. Lytic activities against cell walls of Corynebacterium sepedonicum (Clavibacter michiganense pv. sepedonicum) could be shown with the cell wall extracts of Strep. pyogenes (45.7 kDa), Strep. faecalis (67 kDa), B. megaterium (67 kDa), and Staph. aureus (67 kDa).Key words: autolysins, electrophoresis, hydrolases, muramidases, peptidoglycan.

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