变形杆菌O抗原合成相关糖基转移酶的生物信息学分析及功能鉴定

The applicant have identified two glycosyltransferases, one sugar synthesis enzyme and the active sites of two aminotransferases involved in bacterial surface polysaccharide antigen synthesis supported by the National Natural Science Foundation for the Youth, which supplies a series of elements for monosaccharides and oligosaccharides biosynthesis. The applicant published a total of 11 SCI paper (9 are first or co-first author) based on the project. Oligosaccharides have important biological function, although some glycosyltransferases were identified, it is far away from the real need. The reason for the limitation of glycosyltransferase identification is that the number and type of the proposed glycosyltransferase by bioinformatic methods are not enough. In this project, we will identify lots of O antigen gene clusters of Proteus, whose O antigen structures are almost known. By compare the O antigen gene clusters and O antigen structures, we will propose lots of glycosyltransferases and their functions using bioinformatic methods, which will supply a rich source for glycosyltransferase identification. Then, several glycosyltransferases will be identified biochemically, which will supply some enzyme elements for oligosaccharide synthesis.

在本项目相关的青年科学基金支持下，课题申请人鉴定了与细菌表面多糖抗原合成相关的2种糖基转移酶、1种单糖合成酶，并确定了两种氨基转移酶的活性位点，为生物合成单糖和寡糖提供了一系列酶元件，发表了11篇SCI收录论文（9篇为第一作者或共同第一作者）。寡糖具有重要的生物学功能，目前虽然已经有部分糖基转移酶被鉴定，但还远远无法满足实际需求。究其原因，主要是功能被预测的糖基转移酶的数量和种类还太少，因此阻碍了糖基转移酶元件的挖掘。本课题拟对大量O抗原结构已知的变形杆菌的O抗原基因簇进行破译，通过比较基因簇序列和抗原结构，利用生物信息学方法预测大量潜在的糖基转移酶及其可能的功能，为酶学鉴定这些糖基转移酶提供资源储备。进一步通过对若干糖基转移酶的鉴定，提供一些寡糖合成的酶元件。

寡糖具有重要的生物学功能，目前虽然已经有部分糖基转移酶被鉴定，但还远远无法满足实际需求。究其原因，主要是功能被预测的糖基转移酶的数量和种类还太少，因此阻碍了糖基转移酶元件的挖掘。细菌表面多糖抗原的编码基因簇含有丰富的糖基转移酶资源。申请人前期首次鉴定了变形杆菌O抗原基因簇在基因组上的位置。本课题破译了66种变形杆菌的O抗原基因簇，通过生物信息学方法系统分析O抗原基因簇，并结合已知的O抗原寡糖结构，预测了65种糖基转移酶的功能。在此基础上，运用生物化学方法鉴定了3种糖基转移酶的功能，并对其理化性质和酶活动力学进行了研究。课题发表了7篇SCI论文（影响因子共计18），获得了两项国内发明专利。