Biosynthesis and Assembly of Capsular Polysaccharides

Gram‐negative and Gram‐positive capsular polysaccharides contribute to the bacterial resistance of host immune responses by different mechanisms. Usually, capsular polysaccharides that mask the underlying cell surface structures activate weakly or not at all the immune system, whereas bacterial capsules coexpressed with other bacterial antigens activate the immune system but mask opsonines and prevent complement attack complex formation, as well as phagocytosis.

BIOSYNTHESIS and assembly of capsular polysaccharides …

Regulated expression of polysaccharide utilization and capsular biosynthesis loci in biofilm and ..

in capsular polysaccharide biosynthesis of Streptococcus ..

MacLachllan PR , Keenleyside WJ , Dodgson C and Whitfield C (1993) Formation of the K30: (group I) capsule in Escherichia coli O9:K30 does not require attachment to lipopolysaccharide lipid A‐core. Journal of Bacteriology 175: 7515–7522.

Current understanding on biosynthesis of microbial polysaccharides.

Moxon E and Kroll J (1990) The role of bacterial polysaccharide capsules as virulence factors. Current Topics in Microbiology and Immunology 150: 65–85.

This research has contributed significantly to the understanding of the structure and biosynthesis of capsular polysaccharides.

Biosynthesis and assembly of Group 1 capsular ..

Ohguchi Y , Ishihara Y , Ohguchi M , et al. (2003) Capsular polysaccharide from Actinobacillus actinomycetemcomitans inhibit IL‐6 and IL‐8 production in human gingival fibroblast. Journal of Periodontal Research 38: 191–197.

Complete Tetrasaccharide Repeat Unit Biosynthesis of …

T1 - Regulated expression of polysaccharide utilization and capsular biosynthesis loci in biofilm and planktonic Bacteroides thetaiotaomicron during growth in chemostats

Roberts IS (1996) The biochemistry and genetics of capsular polysaccharide production in bacteria. Annual Review of Microbiology 50: 285–315.

Federal Select Agent Program - Select Agents and …

AB - Heparan sulfate/heparin N-deacetylase/N-sulfotransferase-1 (NDST-1) is a critical enzyme involved in heparan sulfate/heparin biosynthesis. This dual-function enzyme modifies the GlcNAc-GlcA disaccharide repeating sugar backbone to make N-sulfated heparosan. N-sulfation is an absolute requirement for the subsequent epimerization and O-sulfation steps in heparan sulfate/heparin biosynthesis. We have expressed rat liver (r) NDST-1 in Saccharomyces cerevisiae as a soluble protein. The yeast-expressed enzyme has both N-deacetylase and N-sulfotransferase activities. N-acetyl heparosan, isolated from Escherichia coli K5 polysaccharide, de-N-sulfated heparin and completely desulfated N-acetylated heparan sulfate are all good substrates for the rNDST-1. However, N-desulfated, N-acetylated heparin is a poor substrate. The rNDST-1 was partially purified on heparin Sepharose CL-6B. Purified rNDST-1 requires Mn2+ for its enzymatic activity, can utilize PAPS regenerated in vitro by the PAPS cycle (PAP plus para-nitrophenylsulfate in the presence of arylsulfotransferase IV), and with the addition of exogenous PAPS is capable of producing 60-65% N-sulfated heparosan from E. coli K5 polysaccharide or Pasteurella multocida polysaccharide.

f Genetic diversity of capsular polysaccharide biosynthesis in Klebsiella ..

Muhsin Jamal *, Ufaq Tasneem, Tahir Hussain and Saadia Andleeb

Extracellular polysaccharides are as structurally and functionally diverse as the bacteria that synthesise them. They can be present in many forms, including cell-bound capsular polysaccharides, unbound “slime”, and as O-antigen component of lipopolysaccharide, with an equally wide range of biological functions. These include resistance to desiccation, protection against nonspecific and specific host immunity, and adherence. Unsurprisingly then, much effort has been made to catalogue the enormous structural complexity of the extracellular polysaccharides made possible by the wide assortment of available monosaccharide combinations, non-carbohydrate residues, and linkage types, and to elucidate their biosynthesis and export. In addition, the work is driven by the commercial potential of these microbial substances in food, pharmaceutics and biomedical industries. Most recently, bacteria-mediated environmental restoration and bioleaching have been attracting much attention owing to their potential to remediate environmental effluents produced by the mining and metallurgy industries. In spite of technological advances in chemistry, molecular biology and imaging techniques that allowed for considerable expansion of knowledge pertaining to the bacterial surface polysaccharides, current understanding of the mechanisms of synthesis and regulation of extracellular polysaccharides is yet to fully explain their structural intricacy and functional variability.

Biosynthesis and assembly of Group 1 capsular polysaccharides in Escherichia coli and related extracellular polysaccharides in other bacteria

of these capsular polysaccharides.

Küng E , Coward WR , Neill DR , et al (2014) Pneumococcal polysaccharide capsule and pneumolysin differentially affect CXCL8 and IL‐6 release from cells of the upper and lower respiratory tract. PLoS One 9: e92355.