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.
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan.
X
X
Zeng
T
T
Murata
H
H
Kawagishi
T
T
Usui
K
K
Kobayashi
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