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Complex Carbohydrates (complex + carbohydrate)
Selected AbstractsGlycolipid receptor depletion as an approach to specific antimicrobial therapyFEMS MICROBIOLOGY LETTERS, Issue 1 2006Majlis Svensson Abstract Mucosal pathogens recognize glycoconjugate receptors at the site of infection, and attachment is an essential first step in disease pathogenesis. Inhibition of attachment may prevent disease, and several approaches have been explored. This review discusses the prevention of bacterial attachment and disease by agents that modify the glycosylation of cell surface glycoconjugates. Glycosylation inhibitors were tested in the urinary tract infection model, where P-fimbriated Escherichia coli rely on glycosphingolipid receptors for attachment and tissue attack. N -butyldeoxynojirimycin blocked the expression of glucosylceramide-derived glycosphingolipids and attachment was reduced. Bacterial persistence in the kidneys was impaired and the inflammatory response was abrogated. N -butyldeoxynojirimycin was inactive against strains which failed to engage these receptors, including type 1 fimbriated or nonadhesive strains. In vivo attachment has been successfully prevented by soluble receptor analogues, but there is little clinical experience of such inhibitors. Large-scale synthesis of complex carbohydrates, which could be used as attachment inhibitors, remains a technical challenge. Antibodies to bacterial lectins involved in attachment may be efficient inhibitors, and fimbrial vaccines have been developed. Glycosylation inhibitors have been shown to be safe and efficient in patients with lipid storage disease and might therefore be tested in urinary tract infection. This approach differs from current therapies, including antibiotics, in that it targets the pathogens which recognize these receptors. [source] Evidence of high sugar intake, and low fibre and mineral intake, in the gluten-free dietALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2010D. Wild Aliment Pharmacol Ther 2010; 32: 573,581 Summary Background, The only therapy for coeliac disease (CD) is a long-term gluten-free diet (GFD). Little is known about the detailed composition of such a diet. Aim, To clarify the nutritional composition of a GFD and to compare it with a non-GFD diet in representative non-CD populations. Methods, A total of 139 consecutive patients with CD were invited to fill in a prospective validated 5-day food diary, of whom data from 93 were analysed. Results were compared with data from the National Diet and Nutrition Survey of Adults and the UK Women's Cohort Study (UKWCS). Results, Individuals consuming a strict GFD generally had similar intakes of energy and nutrients to those of comparison populations, but a higher proportion of carbohydrate intake was obtained from nonmilk extrinsic sugars and intakes of nonstarch polysaccharides were low. Compared with the UKWCS sample, female patients adhering to a GFD had lower intakes of magnesium, iron, zinc, manganese, selenium and folate. In male patients, intakes of magnesium and selenium were particularly low. Conclusions, This study reinforces the need for clinicians to recognize that avoidance of gluten cannot be the sole focus of a gluten-free diet. Maintenance of adequate intakes of essential nutrients and in particular complex carbohydrates must also be the goal for patients. [source] Merging Organic and Polymer Chemistries to Create Glycomaterials for Glycomics ApplicationsMACROMOLECULAR BIOSCIENCE, Issue 8 2006Géraldine Coullerez Abstract Summary: Oligosaccharides at cell surfaces are known to play a critical role in many biological processes such as biorecognition, interactions between cells and with artificial surfaces, immune response, infection and inflammation. In order to facilitate studies of the role of sugars, an increasing number of novel tools are becoming available. New synthetic strategies now provide much more efficient access to complex carbohydrates or glycoconjugates. Branched carbohydrates and hybrids of carbohydrates conjugated to polymers have been prepared using solution and/or solid-phase synthesis and advanced methods of polymerization. These materials are essential for the development of methodologies to study and map the molecular structure-function relationship at interfaces. This article highlights recent advances in the synthesis of carbohydrates and polymer hybrids mimicking the properties and functionalities of the natural oligosaccharides, as well as selected applications in biology, biotechnology and diagnostics. [source] Glycosyltransferases and their AssaysCHEMBIOCHEM, Issue 14 2010Dr. Gerd K. Wagner Abstract Glycosyltransferases (GTs) are a large family of enzymes that are essential in all domains of life for the biosynthesis of complex carbohydrates and glycoconjugates. GTs catalyse the transfer of a sugar from a glycosyl donor to a variety of acceptor molecules, for example, oligosaccharides, peptides, lipids or small molecules. Such glycosylation reactions are central to many fundamental biological processes, including cellular adhesion, cell signalling and bacterial- and plant-cell-wall biosynthesis. GTs are therefore of significant interest as molecular targets in chemical biology and drug discovery. In addition, GTs have found wide application as synthetic tools for the preparation of complex carbohydrates and glycoconjugates. In order to exploit the potential of GTs both as molecular targets and synthetic tools, robust and operationally simple bioassays are essential, especially as more and more protein sequences with putative GT activity but unknown biochemical function are being identified. In this minireview, we give a brief introduction to GT biochemistry and biology. We outline the relevance of GTs for medicinal chemistry and chemical biology, and describe selected examples for recently developed GT bioassays, with a particular emphasis on fluorescence-based formats. [source] The Structure of Glycosaminoglycans and their Interactions with ProteinsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 6 2008Neha S. Gandhi Glycosaminoglycans (GAGs) are important complex carbohydrates that participate in many biological processes through the regulation of their various protein partners. Biochemical, structural biology and molecular modelling approaches have assisted in understanding the molecular basis of such interactions, creating an opportunity to capitalize on the large structural diversity of GAGs in the discovery of new drugs. The complexity of GAG,protein interactions is in part due to the conformational flexibility and underlying sulphation patterns of GAGs, the role of metal ions and the effect of pH on the affinity of binding. Current understanding of the structure of GAGs and their interactions with proteins is here reviewed: the basic structures and functions of GAGs and their proteoglycans, their clinical significance, the three-dimensional features of GAGs, their interactions with proteins and the molecular modelling of heparin binding sites and GAG,protein interactions. This review focuses on some key aspects of GAG structure,function relationships using classical examples that illustrate the specificity of GAG,protein interactions, such as growth factors, anti-thrombin, cytokines and cell adhesion molecules. New approaches to the development of GAG mimetics as possible new glycotherapeutics are also briefly covered. [source] | ||||||||||