Oligosaccharides, representation

Note. These representations do not follow the recommendations for choice of main chain given in 2-Carb-37.3. Such deviations are common in depicting series of naturally occurring oligosaccharides where it is desirable to show homomorphic relationships. 

Haworth representation, cyclic monosaccharides, 61-63 Hemiacetal groups disaccharides with, 149-150 without, 148-149 nomenclature, 122-123 oligosaccharides with, 153-154 without, 151-153... 

Figure 52-6. Diagrammatic representation of the structures of the H, A,and B blood group substances. R represents a long complex oligosaccharide chain, joined either to ceramide where the substances are glycosphingolipids, or to the polypeptide backbone of a protein via a serine or threonine residue where the substances are glycoproteins. Note that the blood group substances are biantenna ry ie, they have two arms, formed at a branch point (not indicated) between the GIcNAc—R, and only one arm of the branch is shown. Thus, the H, A,and B substances each contain two of their respective short oligosaccharide chains shown above. The AB substance contains one type A chain and one type B chain.

Figure 31-6 Three-dimensional ribbon representation of the structure of a complex of a soluble Fc fragment of a human IgGl molecule. Pro 329 of the IgG and Trp 87 and Trp 110 of the Fc-receptor fragment form a "proline sandwich/ which is shown in ball-and-stick form. The oligosaccharide attached to the Fc fragment of the antibody and the disulfide bridge between the two Cys 229 residues (at the N termini of the C2 domains of the heavy y chains) are also shown. The small spheres on the Fc receptor fragment are potential sites for N-glycosylation. From Sondermann et al.107 Courtesy of Uwe Jacob.

Fig. 5. Schematic representation of the collagen IV molecule, which consists of two al(IV) chains and one a2(IV) chain. The non-triple-helical interruptions of the triple helix are indicated by black bars. The cysteine residues (C) and lysine or hydroxylysine (K) residues putatively involved in intra- or intermolecular bonds are shown. CHO designates a N-giycosidically bound oligosaccharide chain. The subscript numerals indicate the number of residues in a distinct region, summarized for all three a-chains. P designates a main pepsin cleavage site. In interruption 13, the a2(IV) chain forms a 21-residue-long loop, stabilized by an interchain disulfide bridge. NCI, Noncollagenous domain 1 TH, triple-helical domain 7 S, carboxyl-terminal domain.

Figure 9.4 Schematic representation of the macromolecular architecture of a large gel-forming respiratory mucin. Two mucin subunits, each about 500 nm in length, are joined end to end via disulfide bonds (S-S) and consist of oligosaccharide-rich regions (represented by the thickened line) and folded domains stabilized by disulfide bonds (represented by the knots). An expanded portion of one of the oligosaccharide-rich regions (not drawn to scale) shows the variety and density of the attached O-linked glycans...

Figure 16-9. Schematic representation of the complex N-linked oligosaccharides contained in glucocerebrosidase.

Schematic representation of the amino acid sequence of a i -antitrypsin (PiMM) and some of its variants. The amino acid residues shown are not drawn to scale CHO represents the oligosaccharide units.

Fig. 9.7 Schematic representation of oligosaccharides obtained from pork thyroglobuline. The parts without framed units correspond to 9.12. The other oligosaccharides separated are 9.12 + 5, 9.12 + 5 and 6, 9.12 + 5 + 6 + 7 (9.13), and the sulfated dodecasaccharide (9.12 + 5 + 6 + 7 + 8).

Fig. 18.—Diagrammatic Representation of the Oligosaccharides Produced by the Action of Mold Dextranase Preparations on Leuconostoc mesenteroides (Birmingham) Dextran. [The symbols are O, a-D-glucosyl residue 0, o-glucose residue.]...

Carbohydrates are polyhydroxy aldehydes and ketones that are commonly known as sugars. A monosaccharide is a carbohydrate composed of one sugar unit and a disaccharide is a carbohydrate composed of two monosaccharide units. An oligosaccharide is composed of 2-10 monosaccharide units a polysaccharide is composed of 10 or more monosaccharide units. An aldose is a carbohydrate that contains an aldehyde unit and a ketose is a carbohydrate that contains a ketone unit. Monosaccharides are categorized by the total number of carbons in the structure triose, tetrose, pentose, hexose, etc. The d and 1 configurations of a monosaccharide are based on the Fischer projection of d-glyceraldehyde. A Fischer projection is an older representation of sugars. 

Figure 3.249 Schematic representation of oligosaccharides derived from human glycoproteins. In A/-glycosidically bound oligomers, di-A/-acetylchitobiose together with three mannose residues are forming the core of the mannose (a), the complex (b), or the hybrid...

Fig. 10 (a) Schematic representation of the core pentasaccharide (in the dashed box) of N-glycans. The green blocks represent the peptide of the glycoprotein and the yellow blocks represent the oligosaccharide assembly that develops from Ssac. (b) The phenyl-tagged core pentasaccharide (Ssac) and the di- and trisaccharide sub-units selected for the gas-phase conformational investigation... 

Synthesis of Dlsaccharldes and their Derivatives.- Provisional recommendations have been made for abbreviations to be used for the representation of oligosaccharide chains.In the following, compounds are classified according to their non-reducing components but on several occasions it has proved beyond the scope of this treatment to refer to every disaccharide synthesized. 

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