Zeng X, Murata T, Kawagishi H, Usui T, Kobayashi K
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan.
Biosci Biotechnol Biochem. 1998 Jun;62(6):1171-8. doi: 10.1271/bbb.62.1171.
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.
合成了携带N-乙酰乳糖胺（LacNAc）或相关化合物的人工N-糖多肽。首先，用碳酸氢铵将糖类转化为相应的β-糖基胺。然后，将β-糖基胺与聚（L-谷氨酸）的羧基缩合。通过Sephadex G-25柱分离得到不同糖取代度的N-糖多肽。这些合成聚合物被用作分析寡糖-凝集素相互作用的模型化合物。通过琼脂凝胶双扩散试验并根据血凝抑制作用研究了与一些凝集素的相互作用。用LacNAc取代的糖多肽与刺桐凝集素（ECA）、花生（落花生）凝集素（PNA）、蓖麻凝集素-120（RCA120）、小麦胚芽（普通小麦）凝集素（WGA）发生反应，这些凝集素可识别半乳糖基或N-乙酰葡糖胺（GlcNAc）残基。其他携带N-乙酰异乳糖胺、GlcNAc、N，N'-二乙酰壳二糖或N，N'，N''-三乙酰壳三糖的合成糖聚合物也与WGA发生反应，且最后两种聚合物对血凝的抑制作用最强。在这五种糖多肽中，只有用LacNAc取代的那种与ECA发生反应。这些糖取代的糖多肽与相应的凝集素特异性相互作用，无论糖聚合物的糖侧链比天然糖蛋白的糖侧链短多少。
