Synthesis of artificial N-glycopolypeptides carrying N-acetyllactosamine and related compounds and their specific interactions with lectins.
Artificial N-glycopolypeptides carrying N-acetyllactosamine (LacNAc) or related compounds were synthesized. First, sugars were converted into their corresponding beta-glycosylamines with ammonium hydrogen carbonate. Then, the beta-glycosylamines were condensated with the carboxyl groups of poly(L-glutamic acid). N-Glycopolypeptides with different degrees of substitution of sugars were isolated by passage through a column of Sephadex G-25. These synthetic polymers were used as model compounds in the analysis of oligosaccharide-lectin interactions. Interactions with some lectins were investigated by agar-gel double-diffusion tests and in terms of inhibition of hemagglutination. A glycopolypeptide substituted with LacNAc reacted with Erythrina cristagalli agglutinin (ECA), peanut (Arachis hypogaea) agglutinin (PNA), Ricinus communis agglutinin-120 (RCA120), wheat germ (Triticum vulgaris) agglutinin (WGA) lectins, which recognize either galactosyl or N-acetylglucosamine (GlcNAc) residues. Other synthetic glycopolymers carrying N-acetylisolactosamine, GlcNAc, N,N'-diacetylchitobiose, or N,N', N"-triacetylchitotriose also reacted with WGA, and these last two polymers inhibited hemagglutination most. Of these five glycopolypeptides, only the one substituted with LacNAc reacted with ECA. These sugar-substituted glycopolypeptides interacted specifically with the corresponding lectins, no matter how much shorter the sugar side chains of the glycopolymers were than those of natural glycoproteins.
Zeng
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Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan.
Murata
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T
Kawagishi
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H
Usui
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T
Kobayashi
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K
D000362:Agar; D000606:Amino Sugars / Q000032:analysis*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004058:Diffusion; D006020:Glycopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D006385:Hemagglutination Inhibition Tests; D037102:Lectins / Q000737:chemistry*; D008969:Molecular Sequence Data
D000606:Amino Sugars; D006020:Glycopeptides; D037102:Lectins; C000458:N-acetyllactosamine; D000362:Agar