Biosynthesis polysaccharide

A rather limited collection of simple precursor molecules is sufficient to provide for the biosynthesis of virtually any cellular constituent, be it protein, nucleic acid, lipid, or polysaccharide. All of these substances are constructed from appropriate building blocks via the pathways of anabolism. In turn, the building blocks (amino acids, nucleotides, sugars, and fatty acids) can be generated from metabolites in the cell. For example, amino acids can be formed by amination of the corresponding a-keto acid carbon skeletons, and pyruvate can be converted to hexoses for polysaccharide biosynthesis. 

This paper begins with a brief description of pectin structure and an overview of the general mechanism of cell wall polysaccharide biosynthesis. This is followed by a summary of previous research on PGA-GalAT and a description of a facile method to synthesize UDP-[ Cj-galacturonic acid. Finally, the paper ends with a summary of our work on the identificadon, partial characterization, and initial solubilization of the homogalacturonan biosynthetic enzyme PGA-GalAT. 

General mechanisms of plant cell wall polysaccharide biosynthesis... 

The answers to three questions seem the most essential to an understanding of the mechanism of polysaccharide biosynthesis from the chemical point of view ... 

II. Glycosyl Esters of Nucleotides and Polyprenyl Glycosyl Phosphates in Polysaccharide Biosynthesis... 

The structures of polyprenyl diphosphate-linked intermediates of Salmonella O-specific-polysaccharide biosynthesis were confirmed by chemical synthesis of their analogs derived from the plant polyprenols ficaprenol and moraprenol (structurally related to bacterial polyprenol57) with the following study of their behavior as substrates of enzymic reactions. Synthetic polyprenyl a-D-galactopyranosyl diphosphate291,292 was found to serve as an effective acceptor for the transfer of L-rhamnosyl groups.293"295 Two synthetic, isomeric disaccharide derivatives,292 13 and296 14, were tested as acceptors for enzymic D-mannosyl transfer from GDP-Man, but only the former was found to be an efficient substrate.294... 

Beck von Bodman, S., Farrand, S, K. Capsular polysaccharide biosynthesis and pathogenicity in Erwinia stewartii require induction by an N-acylhomoserine lactone autoinducer. J Bacteriol 1995 177 5000-5008. 

This chapter first reviews non-mutant starch granule composition and development and then focuses on genetic mutants and how they have been useful in understanding the complexity of polysaccharide biosynthesis and development. Due to the limitations of space, attention is given only to a few of the plant species which are important sources of commercial starch production the discussion will focus on maize... 

By using mutants of maize and other species, progress has been made in understanding the pathways and enzymes involved in starch biosynthesis and the fine structure of starch polysaccharides. However, starch biosynthesis (Chapter 4) and granule formation are still not completely understood. Thus, integration of the information on polysaccharide biosynthesis (Section 3.6) with that on mutant effects (Section 3.7), is necessary to fully understand polysaccharide biosynthesis and to delineate the limits of this knowledge. 

In addition, to understand the polysaccharide biosynthesis of a species-specific CPS in different Campylobacter species, 6-O-methyl-D-g/ycero-a-L-g/Mco-heptopy-ranose—one of the residues of the tetrasaccharide repeating unit of the CPS of Campylobacter jejuni NCTC 11168—was synthesized [134],... 

Lowary et al. synthesized oligomannoside derivatives to find out the optimal length required by (l 6)-mannosyl transferase for LAM biosynthesis [267, 268] and the specificity of a(l - 4)-mannosy I transferase involved in mycobacterial methylmannose polysaccharide biosynthesis [269], Oligoarabinofuranosides containing C3-modified Ara/residues were also synthesized as the inhibitor of arabinofuranosyltransferases from mycobacteria [270],... 

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