Biochemical-genetic basis of human blood-group MN specificities

The erythrocyte sialoglycoprotein was purified from cells with complementary ABO(H), MN and Ss phenotypes. Serological examination of the sialoglycoprotein preparations demonstrated that this molecule does not carry the ABO(H), I or Ss antigens. The results also suggest that Ss activity may be associated with a minor erythrocyte glycoprotein. The characteristics of the ABO(H) and I antigens are consistent with earlier suggestions that these antigens are carried on complex glycolipids.

Section: Partial Inhibition Onlysupporting

confidence: 68%

Separation of ABH, I, Ss Antigenic Activity from the MN-Active Sialoglycoprotein of the Human Erythrocyte Membrane

Anstee¹,

Tanner²

1975

“…Hence it seems that the inhibitory activity of /S-D-galactosyl-/l->3/-Ar-acetyl-D-galactosamine is dependent on the GalNAc at the reducing end and not on the /i-glycosidically linked galactosyl-residue. As suggested by alkaline degradation and periodate oxidation with subsequent Smith degradation of desialized glycoproteins, the receptor site for the agglutinin may be represented by the GalNAc of the alkali-labile tetrasaccharide, which has been isolated by Thomas and Winzler [42,43], The finding [3] that the M. aurantiaca receptor of En (a-)-erythrocytes is strongly damaged, suggests that the defect of these cells is not restricted to alkali-labile sialic acid and galactose, which is detected by anti-M, -N reagents from rabbits and V. graminea [7,22,25,38,39], but also includes alkali-labile GalNAc.…”

Section: Resultsmentioning

confidence: 99%

“…amara, V. graminea, B. purpurea and M. laevis are only weakly or not at all inhibited by the disaccharide /3-dgalactosyl-/l->-3/-iV-acetyl-D-galactosamine. Another carbohydrate chain consisting of NA, Gal and GalNAc in the molar ratio 1:2:1 [10,38,39] may represent the receptor sites for these agglutinins. However, our recent ob servations (unpubl.…”

Section: Resultsmentioning

confidence: 99%

“…The major component was shown by Thomas and Winzler [42,43] to be a reduced tetrasaccharide having the structure a-A-acetylneuraminyl-/ 2-*-3 j-ß -D-galactosyl-/1-»-3/-(a-A-acetylneuraminyl-/2-»6/-)-A-acetyl-D-galactosaminitol. There are, however, some indications for the occurrence of alkali-labile sialyl-A-acetyl-D-galactosaminyl-residues and oligosaccharides consisting of sialic acid (NA), Gal and A-acetyl-Dgalactosamine (GalNAc) in the molar ratio 1:2:1 [6,10,15,38,39]. These carbohydrate chains may represent the receptor sites for snail anti-A and anti-M, -N agglutinins, respectively.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Further Characterization of some Heterophile Agglutinins Reacting with Alkali-Labile Carbohydrate Chains of Human Erythrocyte Glycoproteins

Dahr¹,

Uhlenbruck²,

Bird³

1975

The nature of the receptor sites for several agglutinins is characterized by hemagglutination inhibition assays. The inhibitory activity of human erythrocyte glycoproteins, from which sialic acid, sialic acid and galactose or alkali-labile oligosaccharides have been removed, is compared to the inhibitory effect of compounds with known structure. It is shown that the lectin from Arachis hypogea and anti-T bind to alkali-labile galactosyl-residues. Agglutinins from Bauhiniapurpurea and variegata (non- or N-speciflc), Maclura aurantiaca, Iberis amara, sempervirem, umbellata hybrida and umbellata nana (M- or nonspecific), Moluccella laevis (A- plus N-specific), Helix pomatia, Helix aspersa, Helix lucorum and Caucasotachea atrolabiata interact with alkali-labile V-acetylgalactosamine. The results obtained with the anti-A agglutinins from various snails suggest that human erythrocyte glycoproteins contain, besides the alkali-labile tetrasaccharide, a peptide-linked sialyl-N-acetyl-galactosaminyl-residue. The investigations do not allow a precise definition of the receptor sites for the lectins having M- or N-specificity.

“…[ 35] have shown that the polyagglutinable cell population has a diminuition or abolition of the receptor sites for MN-antibodies and the lectins from Vicia graminea and Arachis hypogoea which are directed against alkali labile NA and Gal, respectively [11,13,16,26,32,33].…”

Section: -Jv-acetylneuraminyl-(2-*-3)-/j-d-galactosyl-(l-*-3)-[a-7v-amentioning

confidence: 99%

Molecular Basis of Tn-Polyagglutinability

Dahr¹,

Uhlenbruck²,

Gunson³

et al. 1975

Spectrophotometric and gas-liquid chromatographic analyses on the carbohydrate moiety of tryptic erythrocyte glycopeptides from persons with Tn-syndrome reveal a selective lowering of the galactose and sialic acid content, the degree being dependent on the percentage of polyagglutinable cells. Alkaline borohydride specifically releases N-acetylgalactosaminitol, and the amount is correlated to the percentage of pathological erythrocytes. It is concluded that the alkali-labile carbohydrate chains of Tn-polyagglutinable red cells solely consist of TV-acetylgalactosamine linked to serine or threonine. Experiments with heterophile agglutinins whose specificity is known are in line with the above-mentioned results. As judged from SDS-polyacrylamide gel electrophoresis the three major membrane glycoproteins are affected to a different extent by the defect.