Preparation of Oligosaccharaide Units Library Involved in Glycoconjugate and Its Utilization

我们通过糖苷酶介导的糖基化和糖基转移酶，建立了一些涉及糖共轭的二糖、三糖和四糖的合成路线。这些合成的低聚糖被用来制备糖共聚物作为碳水化合物-蛋白质相互作用研究的探针。粘蛋白型寡糖Galbeta1-3(GlcNAcbeta1-6)GalNAcalpha-OC_6H_4NO_2-p(1)是粘蛋白2型核心碳水化合物区域，由GalNAcalpha-OC_6H_4NO_2-p和GalNAcalpha-OC_6H_4NO_2-p连续伸长而成。通过乳糖半乳糖化反应合成了Galbeta1-3GalNacalpha-OC_6H_4NO_2-p(2)。通过诺卡氏菌β-N-乙酰己糖苷酶介导的糖基化反应将产物2转化为目标化合物1。N-乙酰氨基葡萄糖苷(3，trisaccharide3‘-O-beta-N-acetylglucosaminyl-N-acetyllactosamine)是聚-N-乙酰乳糖胺的常见三糖单元，通过N-乙酰氨基葡萄糖转移反应合成N-乙酰氨基己糖苷(3，GlcNAcbeta1-3Galbeta1-4GlcNAcbeta-OC_6H_4NO_2-p)，)。在这种情况下，当使用对硝基苯基β-N-乙酰乳糖胺受体与α-环糊精的包合物时，糖苷酶介导的目标三糖苷(3)的区域选择性发生了很大的变化。将糖基共聚体N-乙酰乳糖胺及其相关化合物转化为人工糖共聚物。合成了两种主链为聚丙烯酰链和聚谷氨酸SCID多肽链的糖共聚物，并将其用于寡糖选择分析。这些水溶性的糖共聚物能够与相应的凝集素特异性地相互作用，无论聚合物中有多少个侧链是短链的，如二糖单元。

We established some synthetic routes of di-, tri, and tetrasaccharides, which are involved in glycoconjugate, through glycosidase-mediated transglycosylation and glycosyltransferase. These synthetic oligosaccharides were used for preparing glycopolymer as probes in carbohydrate-protein interaction studies.1. Mucin-type oligsaccharideGalbeta1-3 (GlcNAcbeta1-6) GalNAcalpha-OC_6H_4NO_2-p (1), whichis a carbohydrate region of mucin type 2 core, was enzymatically by the consecutive elongation of Gal and GlcNAcresidues to GalNAcalpha-OC_6H_4NO_2-p in two stages. Galbeta1-3GalNAcalpha-OC_6H_4NO_2-p (2) was firstly prepared by using galactosyl ation from lactose to GalNAcalpha-OC_6H_4NO_2-p. The resulting 2 was transformed into the desired compound 1 through Nocardia orientalis beta-N-acetylhexiosaminidase-mediated transglycosylation.2. N-Acetylglucosdaminyl trisaccharide3'-O-beta-N-acetylglucosaminyl-N-acetyllactosamine glycoside (3, GlcNAcbeta1-3Galbeta1-4GlcNAcbeta-OC_6H_4NO_2-p), which is the common trisaccharide unit of poly-N-acetyllactosamine, was synthesized through N-acetylglucosaminyl transfer by beta-N-acetylhexosaminidase from N.orientalis. In this case, when an inclusion complex of p-nitrophenyl beta-N-acetyllactosamine acceptor with alpha-cyclodextrin was used, the regioselectivity of glycosidase-mediated formation of the desired trisaccharide glycoside (3) was substantially changed.3. GlycopolymerN-Acetyllactosamine and its related compounds were used to transform into artificial glycopolymer. Two types of glycopolymers, whose main chain are polyacryl chain and polyglutamic scid peptide chain, were synthesized and used as modelin oligosaccharide-lection analysis. These water-soluble glycopolymers were shwon to interact specifically with the corresponding lectin, no matter how many side chains of the polymers are short-chain length such as disaccharide unit.