Shengshu Huang, Hai Yu, Xi Chen
Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA.
Sci China Chem. 2011 Jan;54(1):117-128. doi: 10.1007/s11426-010-4175-9.
Sialic acids are common terminal carbohydrates on cell surface. Together with internal carbohydrate structures, they play important roles in many physiological and pathological processes. In order to obtain α2-3-sialylated oligosaccharides, a highly efficient one-pot three-enzyme synthetic approach was applied. The P. multocida α2-3-sialyltransferase (PmST1) involved in the synthesis was a multifunctional enzyme with extremely flexible donor and acceptor substrate specificities. Sialyltransferase acceptors, including type 1 structure (Galβ1-3GlcNAcβProN(3)), type 2 structures (Galβ1-4GlcNAcβProN(3) and 6-sulfo-Galβ1-4GlcNAcβProN(3)), type 4 structure (Galβ1-3GalNAcβProN(3)), type 3 or core 1 structure (Galβ1-3GalNAcαProN(3)) and human milk oligosaccharide or lipooligosaccharide lacto-N-tetraose (LNT) (Galβ1-3GlcNAcβ1-3Galβ1-4GlcβProN(3)), were chemically synthesized. They were then used in one-pot three-enzyme reactions with sialic acid precursor ManNAc or ManNGc, to synthesize a library of natural occurring α2-3-linked sialosides with different internal sugar units. The sialylated oligosaccharides obtained are valuable probes for their biological studies.
唾液酸是细胞表面常见的末端碳水化合物。它们与内部碳水化合物结构一起，在许多生理和病理过程中发挥重要作用。为了获得α2-3-唾液酸化寡糖，采用了一种高效的一锅三酶合成方法。参与合成的多杀巴斯德菌α2-3-唾液酸转移酶（PmST1）是一种多功能酶，其供体和受体底物特异性极具灵活性。化学合成了唾液酸转移酶受体，包括1型结构（Galβ1-3GlcNAcβProN(3)）、2型结构（Galβ1-4GlcNAcβProN(3)和6-磺基-Galβ1-4GlcNAcβProN(3)）、4型结构（Galβ1-3GalNAcβProN(3)）、3型或核心1结构（Galβ1-3GalNAcαProN(3)）以及人乳寡糖或脂寡糖乳糖-N-四糖（LNT）（Galβ1-3GlcNAcβ1-3Galβ1-4GlcβProN(3)）。然后将它们用于与唾液酸前体ManNAc或ManNGc的一锅三酶反应中，以合成具有不同内部糖单元的天然存在的α2-3-连接唾液酸苷文库。所获得的唾液酸化寡糖是用于其生物学研究的有价值的探针。
