Types of Glycans

The glycans attached to proteins fall into two categories [1,2], but the techniques used for their analysis are the same  

FIGURE 8.1 Glycan structures drawn using the symbolic nomenclature from University of Oxford (UOXF), Consortium of Functioal Glycomics (CFG), or text oniy. 

GlcNAc2 core. Hybrid glycans are those in which only the Manal,3-arm of the core has GlcNAc antennae attached. 

Glycans are also foimd attached to lipids, where the lipid portion of the 

Glycophospholipids, built on a phosphatidylglycerol core, which anchor proteins to the cell surface. 

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Fig. 45.—Pathway of the Biosynthesis of Lipid-linked Oligosaccharide Precursor of the N-Acetyl-lactosaminic Type of Glycans, and of the Intermediary Glycopeptide. (See general reviews 126-136, 226, and 227.)...

Kitajima et al. [264] used the mixture of mercury salts and molecular sieves in 1,2-dichloromethane to condense (370) with the trisaccharide derivative (382) to give similar tetrasaccharides [on the primary hydroxyl group of (382)] with again equal amounts (30% each) of a- and (3-linked derivatives. With the allyl glycoside (383) under the same conditions 48 % of a- and 33 % of P-linked glycosides were obtained [265]. The a-isomer was used to prepare [265] the undecasaccharide characteristic of the complex type of glycan of glycoproteins. 

Ogawa, T, Sugimoto, M, Kitajima, T, Sadozai, K K, Nukada, T, Synthetic studies on cell surface glycans. 51. Total synthesis of an undecasaccharide. A t)fpical carbohydrate sequence for the complex type of glycan chains of a glycoprotein. Tetrahedron Lett., 27, 5739-5742, 1986. 

The choice of analysis modules employed in a glycoprofiling scheme and the procedures used in each module is influenced by many factors including what types of glycans are possible in... 

Year Array Type of Glycans Glycan Type Glycan Source Immobilization Method Application References... 

From 2004 Defined 200 to 600 All types of glycans Mixed Amine-NHS Various (60)... 

The type of glycan is not randomly distributed along the peptide chain. Asn-251 site contains glycans of the iV-acetyllactosaminic type while Asn-727 is entirely of the oligomannosidic type [142,143]. Glycans linked to Asn-317 are a mixture of glycans of the 7/-acetyllactosaminic, oligomannosidic and hybrid type [144]. 

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