Chemical syntheses are reported for GDP-fucose (5), GDP-3-deoxy-fucose (6), and GDP-arabinose (7), the demethyl analog of 5. All three sugar nucleotides were found to act as donor substrates for an α(1 → 4) fucosyltransferase isolated from human milk when *BDGal(1 → 3)*BDGlcNAc-O(CH2)8COOMe (1) was used as the acceptor. The rate of transfer of sugar residues to 1 was measured using a coupled spectrophotometric assay and was found to be 100% (5), 2.3% (6), and 5.9% (7). The product Lea-active oligosaccharide analogs were identified by both an enzyme-linked immunosorbent assay (ELISA) and by 1H NMR spectroscopy. Keywords: glycosyltransferase, oligosaccharide synthesis, sugar-nucleotide analog, ELISA assay, fucosyltransferase.
报道了GDP-岩藻糖(5)、GDP-3-去氧岩藻糖(6)和GDP-阿拉伯糖(7)的化学合成,其中7是5的去甲基类似物。当以*BDGal(1 → 3)*BDGlcNAc-O(CH2)8COOMe (1)作为受体时,发现这三种糖核苷酸都能作为人乳中分离的α(1 → 4)岩藻糖基转移酶的供体底物。使用耦合分光光度法测量糖残基转移速率,发现对1的转移率分别为100%(5)、2.3%(6)和5.9%(7)。通过酶联免疫吸附试验(ELISA)和1H NMR光谱法鉴定了产物Lea-活性寡糖类似物。关键词:糖基转移酶、寡糖合成、糖核苷酸类似物、ELISA检测、岩藻糖基转移酶。