Staphylococcus cell wall

The tumoricidal activity of MRAMs containing either doxorubicin or protein A, a constituent of the cell wall of Staphylococcus aureus, was tested in rats with induced mammary adenocarcinoma (138). 

In the cell-wall antigen from Staphylococcus aureus M, taurine is linked as an amide (51) to a 2-acetamido-2-deoxy-D-galactosyluronic residue. l-Threonine and L-glutamic acid are linked as amides to D-glucuronic acid residues in the LPS from Rhodopseudomonas sphaeroides ATCC 17023 and in the capsular polysaccharide from Klebsiella K82, respectively. In the capsular polysaccharide from E. coli K54, L-serine and L-threonine, in the ratio 1 9, are linked to the carboxyl group of a D-glucuronic acid residue. In the capsular polysaccharide from Haemophilus influenzae type d,... 

Protein A is a cell-wall protein of Staphylococcus aureus with a molecular weight of 42,000. Since protein A binds specifically to the Fc part of IgG from various animals, it has been widely used in immunoassay and affinity chromatography. We found that protein A could be spread over the water surface to form a monolayer membrane by the LB method [21]. On the basis of this finding, an antibody array on the solid surface can be obtained by the following two steps. The first step is fabrication of an ordered protein A array on the solid surface by the LB method. The second step is self assembly of antibody molecules on the protein A array by biospecific affinity between protein A and the Fc of IgG as shown in Fig.34. 

Taylor, J. M. and Heinrichs, D. E. (2002). Transferrin binding in Staphylococcus aureus involvement of a cell wall-anchored protein, Mol. Microbiol., 43, 1603-1614. 

Figure 1.3. Phagocytosis of Staphylococcus aureus by a human neutrophil. Neutrophils were incubated with opsonised S. aureus and fixed after 15 min incubation. The bacterium in the centre has been lysed, and only the cell wall remains. Source Experiment of Bernard Davies and John Humphreys, reproduced with permission from Colour Atlas of Paediatric Infectious Diseases, by Hart and Broadhead (Mosby Year Book Europe).

In contrast to Gram-negatives, many Gram-positive bacteria employ post-translationally modified peptides processed from larger precursors as QS signal molecules. In Staphylococcus aureus, for example, a family of peptide (7-9 amino acid residues) thiolactones which vary in the primary amino acid sequence but contain a conserved cysteine at position 5 control the expression of cell wall colonization factors and exotoxins [24-26]. 

Downer, R., Roche, F., Park, P. W., Mecham, R. P., and Foster, T. J. (2002). The elasin-binding protein of Staphylococcus aureus (EbpS) is expressed at the cell surface as an integral membrane protein and not as a cell wall-associated protein. /. Biol. Chem. 277, 243-250. 

The main function of the ester 34 in bacterial cells seems to be its participation in the biosynthesis of the glycopeptide cell-wall polymer. If this process is blocked, there results the accumulation of a high concentration of sugar nucleotide precursors in the cell. A number of these compounds have been isolated the simplest one is the ester of uridine 5 -pyrophosphate with N-acetylmuramic acid [2-acetamido-3-0-(D-l-carboxyethyl)-2-deoxy-D-glucose] (37), first obtained from Staphylococcus aureus cells that had been treated with penicillin7,151 or Gentian Violet.144 An intermediate in the biosynthesis of 37 was isolated and shown to be the 3 -enolpyruvate ether152,153 (38). 

Poly(ribitol phosphate) synthetase has been found in particulate fractions from Staphylococcus aureus H, and Lactobacillus plantatrum.lt ll-m The bulk of the activity in Lactobacillus plantarum was in crude, cell-wall preparations, and the enzyme is apparently located in the membrane, although intimate association with the wall itself has been suggested. Unlike the natural teichoic acid, the enzymically synthesized ribitol phosphate polymer was readily extracted with phenol hydrolysis by acid and by alkali gave the expected products, and oxidation with periodate indicated a chain length of 5-9 units, a value which compares well with that of 8 units for the natural polymer in the walls of this organism. 

Polysaccharide-1-phosphates were extracted in some cases from bacterial cell walls. For example, TA isolated from Staphylococcus lactis 2102 consists of ca. 23 monomeric fragments each built of a-D-N-acetylglucosamine-1 -phosphate 22). These units are linked by the phosphoester bond at the 6 position in the sugar residue, as represented by 7. 

The third stage of cell wall synthesis. This diagram shows the cross-linking reaction and the mechanism of inhibition by penicillin in the bacterium Staphylococcus aureus. 

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