Lectins oligosaccharides

The carbohydrate-binding specificity of purified Dolichos biflorus lectin has been studied in detail by Etzler and Kabat.108 In precipitin studies conducted on the Dolichos lectin, 87-99% was precipitated by ovarian cyst A substance, whereas only 60-70% was precipitated by hog A substance the latter result was attributed to the formation of soluble, lectin-oligosaccharide complexes. At substances were more reactive than A2 substances however, no reaction was observed with B or O substances, even following mild hydrolysis with acid or two stepwise, Smith degradations. N-Deacetylation of A substance with... 

Nakamura-Tsuruta S, Uchiyama N, Hirabayashi J (2006) High-throughput analysis of lectin-oligosaccharide interactions by automated frontal affinity chromatography. Methods Enzymol 415 311-325... 

Table 5. References and selected structural information for the crystal structures of lectin-oligosaccharide crystal structures. ... 

Numerous lectins have been purified and are commercially available three plant lectins that have been widely used experimentally are listed in Table 47-7. Among many uses, lectins have been employed to purify specific glycoproteins, as tools for probing the glycoprotein profiles of cell surfaces, and as reagents for generating mutant cells deficient in certain enzymes involved in the biosynthesis of oligosaccharide chains. 

Incomplete (N-linked) glycosylation prompts decreased in vivo activity due to more rapid hepatic clearance of the EPO molecule. Enzymatic removal of terminal sialic acid sugar residues from oligosaccharides exposes otherwise hidden galactose residues. These residues are then free to bind specific hepatic lectins, which promote EPO removal from the plasma. The reported plasma tm value for native EPO is 4-6 h. The tm for desialated EPO is 2 min. Comparison of native human EPO with its recombinant form produced in CHO cells reveals very similar glycosylation patterns. 

The first allosteric modulators discovered to act on AMPA/KA receptors were the plant lectins, including concanavalin A (ConA), that block receptor desensitization, probably through binding to Y-1 inked oligosaccharides (51,52). It was soon discovered that certain benzothiazides, such as diazoxide and cyclothiazide, also act on the same allosteric site controlling non-NMDA receptor desensitization (53-55). Interestingly, ConA and cyclothiazide show high selectivity for KA and AMPA receptors, respec-... 

The final chapter is dedicated to the state-of-the-art methods for determining lectin affinity and specificity for oligosaccharides. These play a key role in many biological processes relevant to cell communication and disease states, and are involved in cancer development and metastasis, inflammation and host-pathogen recognition. 

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