Teichoic acids (cf. Greek τεῖχος, teichos, "wall")[1] are bacterial polysaccharides[2] of glycerol phosphate or ribitol phosphate linked via phosphodiester bonds.
Location and structure
Teichoic acids are found within the cell wall of Gram-positive bacteria such as species in the genera Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium and Listeria, and appear to extend to the surface of the peptidoglycan layer. Teichoic acids are not found in Gram-negative bacteria. They can be covalently linked to N-acetylmuramic acid of the peptidoglycan layer, to the lipids of the cytoplasmic membrane, or to a terminal D-alanine in the tetrapeptide crosslinkage between N-acetylmuramic acid units. The combination of teichoic acids and lipids are referred to as lipoteichoic acids.
Function
The main function of teichoic acids is to provide rigidity to the cell-wall by attracting cations such as magnesium and sodium. Teichoic acids are usually, but not always, substituted with D-alanine ester residues,[3] giving the molecule zwitterionic properties.[4] These zwitterionic teichoic acids are suspected ligands for toll-like receptors 2 and 4. Teichoic acids also assist in regulation of cell growth by limiting the ability of autolysins to break the β(1-4) bond between the N-acetyl glucosamine and the N-acetylmuramic acid.
Lipoteichoic acids also act as receptor molecules for some Gram-positive bacteriophage.[5] Evidence suggests teichoic acid may act as a bacteriophage receptor; however, this has not yet been conclusively proven.
See also
References
- ^ τεῖχος. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at Perseus Project
- ^ Teichoic+acids at the US National Library of Medicine Medical Subject Headings (MeSH)
- ^ Knox KW, Wicken AJ (June 1973). "Immunological properties of teichoic acids". Bacteriological Reviews 37 (2): 215–57. PMC 413812. PMID 4578758. http://mmbr.asm.org/cgi/pmidlookup?view=long&pmid=4578758.
- ^ Garimella R, Halye JL, Harrison W, Klebba PE, Rice CV (October 2009). "Conformation of the phosphate D-alanine zwitterion in bacterial teichoic acid from nuclear magnetic resonance spectroscopy". Biochemistry 48 (39): 9242–9. doi:10.1021/bi900503k. PMID 19746945.
- ^ Raisanen, L., Draing, C., Pfizenmaier, M., Schubert, K., Jaakonsaari, T., Aulouck, S., Hartung, T. and Alatossava, T. (June 2007). "Molecular interaction between lipoteichoic acids and Lactobacillus delbrueckii phages depends on the D-Alanyl and a-glucose substituion of poly(glycerophosphate) backbones". J.Bac: 4135–4140.