Multifunctionality of Campylobacter jejuni sialyltransferase CstII:: Characterization of GD3/GT3 oligosaccharide synthase, GD3 oligosaccharide sialidase, and trans-sialidase activities
Multifunctionality of Campylobacter jejuni sialyltransferase CstII:: Characterization of GD3/GT3 oligosaccharide synthase, GD3 oligosaccharide sialidase, and trans-sialidase activities
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DOI：
10.1093/glycob/cwn047
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发表时间：
2008-09-01
期刊：
影响因子：
4.3
通讯作者：
Chen, Xi
中科院分区：
文献类型：
--
作者：
Cheng, Jiansong;Yu, Hai;Chen, Xi
来自细菌空肠弯曲杆菌菌株OH 4384的Cst II先前已被表征为双功能唾液酸转移酶，其具有α 2，3-唾液酸转移酶（GM 3寡糖合酶）和α 2，8-唾液酸转移酶（GD 3寡糖合酶）活性，其催化N-乙酰神经氨酸（Neu 5Ac）从胞苷5 '-单磷酸（CMP）-Neu 5Ac转移到C-分别连接到乳糖中半乳糖的3 '和3 '-唾液酸乳糖中Neu 5Ac的C-8（吉尔伯特M，Karwaski MF，Bernatchez S，Young NM，Taboada E，Michniewicz.J，Cunningham AM，Wakarchuk WW. 2002.空肠弯曲菌脂寡糖变异的遗传基础。核心寡糖中唾液酸化神经节苷脂模拟物的生物合成。J Biol Chem.277：327-337）。我们在这里报告的表征截短CstII突变体（CstII三角洲32（153 S））克隆从一个合成的基因，其密码子优化的大肠杆菌表达系统。除了之前报道的分别用于合成GM 3型和GD 3型寡糖的α 2，3-和α 2，8-唾液酸转移酶活性外，CstIIA 32（153 S）还具有用于合成GT 3寡糖的α 2，8-唾液酸转移酶（GT 3寡糖合酶）活性。还具有α 2，8-唾液酸酶（GD 3寡糖唾液酸酶）活性，可催化GD 3型寡糖的α 2，8-唾液酸键的特异性裂解，以及α 2，8-转唾液酸酶（GD 3寡糖转唾液酸酶）活性，可催化唾液酸从GD 3寡糖转移至不同的GM 3寡糖（3-唾液酸乳糖苷）。CstIIA 32（153 S）GD 3寡糖合成酶活性的供体底物特异性研究表明，该酶在使用不同的CMP活化的唾液酸及其类似物合成末端唾液酸含有天然和非天然修饰的GD 3寡糖方面具有灵活性。
CstII from bacterium Campylobacter jejuni strain OH4384 has been previously characterized as a bifunctional sialyltransferase having both alpha 2,3-sialyltransferase (GM3 oligosaccharide synthase) and alpha 2,8-sialyltransferase (GD3 oligosaccharide synthase) activities which catalyze the transfer of N-acetylneuraminic acid (Neu5Ac) from cytidine 5 '-monophosphate (CMP)-Neu5Ac to C-3 ' of the galactose in lactose and to C-8 of the Neu5Ac in 3 '-sialyllactose, respectively (Gilbert M, Karwaski MF, Bernatchez S, Young NM, Taboada E, Michniewicz.J, Cunningham AM, Wakarchuk WW. 2002. The genetic bases for the variation in the lipo-oligosaccharide of the mucosal pathogen, Campylobacter jejuni. Biosynthesis of sialylated ganglioside mimics in the core oligosaccharide. J Biol Chem. 277:327-337). We report here the characterization of a truncated CstII mutant (CstII Delta 32(153S)) cloned from a synthetic gene whose codons are optimized for an Escherichia coli expression system. In addition to the alpha 2,3- and alpha 2,8-sialyltransferase activities reported before for the synthesis of GM3- and GD3-type oligosaccharides, respectively, the CstIIA32(153S) has alpha 2,8-sialyltransferase (GT3 oligosaccharide synthase) activity for the synthesis of GT3 oligosaccharide. It also has alpha 2,8-sialidase (GD3 oligosaccharide sialidase) activity that catalyzes the specific cleavage of the alpha 2,8-sialyl linkage of GD3-type oligosaccharides and alpha 2,8-trans-sialidase (GD3 oligosaccharide trans-sialidase) activity that catalyzes the transfer of a sialic acid from a GD3 oligosaccharide to a different GM3 oligosaccharide (3-sialyllactoside). The donor substrate specificity study of the CstIIA32(153S) GD3 oligosaccharide synthase activity indicates that the enzyme is flexible in using different CMP-activated sialic acids and their analogs for the synthesis of GD3 oligosaccharides containing natural and nonnatural modifications at the terminal sialic acid.