Blood groups A determinant

Prevalence in Asian Strains The Lewis A, B, D, and Blood-Group A Determinants 130... 

Fuc(al-4) were also observed in A. maculatum (Fig. 4). Other unusual sequences, namely the dimer H epitope Fuc(al-2)Gal(Pl-3)[Fuc(al—2)]Gal, and blood group A determinant terminated with an additional a-l,3-linked GlcNAc unit, were found in X. laevis (Fig. 5). 

The rational design of glycosyltransferase inhibitors has been on substrate mimicry. For example, Lowary and coworkers synthesized 3-amino-3-deoxy(Fucal-2)Gal/3-0(CH2)7CH3 as a competitive inhibitor of the blood group A A-acetylgalactosaminyltransferase (Figure 16(i)). The administration of this compound to cells afforded only a modest reduction of the blood group A determinant expression, which was attributed to... 

Figure 25.12 Structures of the A, B, and 0 blood-group antigenic determinants.

Kukowsaka-Fatallo, J. F., R. D. Farsen, R. P. Nair, and J. B. Fowe, A cloned human cDNA determines expression of a mouse stage-specific embryonic antigen and the Lewis blood group a(l,3/l,4)fucosyltransferase. Genes Dev. 4 1288-1303, 1990. 

Ten sialic-acid-containing oligosaccharides and four neutral oligosaccharides have been purified from the major glycoprotein fraction of hog, submaxillary-gland mucin. H-N.m.r. spectroscopy at 360 MHz, in combination with methylation analysis and mass spectrometry, allowed the determination of their structures, which are partial structures of a pentasaccharide (see Fig. 42) having blood-group A activity.221... 

Paulsen and co-workers [191] synthesised the trisaccharide (263) representing the afucosyl end group of the blood-group A (type 1) determinant from the disaccharide (264). This was acetylated and deacetonated and the product converted into the acetate (265) via the 3, 4 -orthoacetate. Condensation of (265) with the azido-chloride (237) in the presence of silver perchlorate gave the a-linked trisaccharide (266) which was deprotected to give (263). 

The Lewis a (Lea) blood-group trisaccharide determinant (345) first synthesised by Lemieux and co-workers [25] was also prepared by Sinay and co-workers [222] using the imidate procedure [232]. Condensation of the fucosyl imidate (321) with the disaccharide (346), prepared via the allyl ether (347), in the presence of toluene p-... 

G. Schiffman, E. A. Kabat, and W. Thompson, Immunochemical studies on blood groups. XXXn. Immunochemical properties of and possible partial structures for the blood group A, B, and H antigenic determinants, Biochem. J., 3 (1964) 587-593. 

The Chemical Synthesis of 2-Acetamido-2-deoxy-4-(3-(a-L-fucopyra-nosyl)-3-<9-(/l-D-galactopyranosyl)-D-glucose. The Lewis a Blood-Group Antigenic Determinant, R. U. Lemieux and H. Driguez, J. Am. Chem. Soc., 97 (1975) 4063 1069. 

The first physico-chemical determination appears to be that of Kekwick.116 He examined in the ultracentrifuge the material prepared from ovarian cyst fluid which showed blood-group A specificity.117 This product was electrophoretically homogeneous and only one component was apparent in the sedimentation measurements. The complex was moderately polydisperse and possessed a highly asymmetric shape (f/fo = 3.2). The values of the sedimentation and diffusion constants, interpolated graphically at a given concentration, corresponded to a mean molecular weight of 260,000... 

Structurally, the O-polysaccharide chains of H. pylori clinical isolates have a poly-A-acetyl-lactosamine (-LacNAc) chain decorated with multiple lateral a-L-fucose residues forming internal Lex determinants with terminal Lex or Ley units (Fig. 10.4) or, in some strains with additional, D-glucose or D-galactose residues (Moran 2001 a,b, 2008 Monteiro, 2001). Moreover, Lea, Leb, sialyl-Lex, and H-1 antigens have been structurally described in other strains, as well as the related blood groups A and B (Fig. 10.4), but occur in association with Lex and LacNAc chains (Monteiro et al., 2000a,b Heneghan et al., 2000). 

The procedure has been employed for the synthesis of the determinant trisaccharide unit of the human blood group A using 2-28 and the (-)-menthyl glyoxylate 2-27 as a matched pair to give the desired disaccharide 2-30 after isomerisation of the primarily obtained mixture of 2-29 and 2-30. 

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