研究糖蛋白糖链结构，通常需要将糖链从糖蛋白上释放下来。由于现有释放N，O-糖链的方法具有局限性，影响了后续分析鉴定。本课题拟在我们已初步建立的O-糖链非还原性释放方法基础上，进一步深入系统研究碱催化的N，O-糖链释放过程，根据N和O-糖肽键及结构类型不同的糖链在碱性环境中稳定性不同，按分析需要选择不同条件，在同时存在N和O-糖基化情况下，实现特异性高效定量释放N或O-糖链，或N,O-糖链同时释放，重点解决糖链在释放过程中的降解问题，进而发展通用的N,O-糖链释放方法体系；以质谱和液-质联用技术为检测手段，建立基于释放基础之上的糖链高灵敏度分析鉴定方法，对PMP标记的糖链全甲基化后的质谱碎片裂解行为进行研究，构建糖链碎片图谱库。本课题研究将进一步完善和改进现有微量糖链释放、标记、富集及定性定量分析方法体系，对发展新的高通量糖链序列结构分析策略有重要意义，也将为糖链结构与功能关系研究提供手段。

Generally, release of glycan from skeleton protein by a suitable and efficient method is especially essential to elucidate their structure. However, the existed methods for release N, O-glycans from glycoprotein suffer from some limitations and drawbacks. Hence, the detection of N,O-glycosylations has been hindered to some extent. In our previous work, we have preliminarily established and reported an innovative route for non-reductive release and analysis of O-glycans from glycoprotein. Our current studies will systematically examine and evaluate the alkali catalytic N, O-glycan release process according to the structure and stability difference of N/O- glycopeptide bond under alkali conditions, and establish a universal and non-reductive release methods for specific O- or N-glycans as well as both O-and N-glycans. The studies will emphatically focus on establishment of the novel and unified approach for O/N-glycan liberation and prevent peeling degradation in the process of release procedure. Furthermore, with the strengths of mass spectrometry and liquid chromatography -mass spectrometry technique, we will employ the develped release method that could release N-, O-, and N/O-glycans from glycoprotein and show compatibility with subsequent permethylation, to establish an high sensitive analysis methods for the detection of N/O-glycans and provide an avenue to build a tandem MS fragment database of glycans. Our studies will improve the existing methods for microscale N/O-glycan releasing, labeling, capturing, qualitative and quantitative detection, which will definitely facilitate the development of high throughput sequencing glycans, illustrating the methological significance in structure-function relationship studies.