Studies Of Glycosylation Analysis Methods Based On Lectin Microarray And Magnetic Silica Microsphere

Glycosylation is an important post-translational modification,and plays an important role in differentiation,development,reproduction,metabolism,aging and immunity.Abnormal glycosylation correlates closely with the occurrence and development of various diseases,especially cancers.Glycans have significant clinical value in helping early screening and diagnosis,progression monitoring,prognosis evaluation of various diseases,and glycosylation promises to be an important supplementary biomarker which can improve diagnostic accuracy,instruct scientifically disease treatment,and develop novel clinical treatment strategies.The first priority is to develop simple and efficient methods for glycosylation analysis,this dissertation focuses on the development and improvement of analysis methods relative to glycans,mainly containing two parts based on lectin microarray technology and magnetic silica microspheres,respectively.Lectin microarray technology is suitable for the analysis of large clinical samples because of the advantages of high throughput,high sensitivity and simple operation.The first part of this dissertation optimized a glycoprotein analysis method based on the lectin microarray technology and analysis methods of big data.Then we applied lectin microarray in differential analysis of IgG glycosylation profiles between patients with solid nodule(SN)and ones with ground glass nodule(GGN),discovered lectin probes that were specific to some significantly differentiallyexpressed glycans between patients from diffierent groups,and proved the potential clinical application value of serum IgG glycosylation as a new noninvasive serological marker for early screening and diagnosis of lung cancer in small samples,which would provide strong technical and theoretical supports for follow-up further studies in large-scale clinical trials.In early studies,our research group developed a kind of magnetic silica microsphere containing an organic modification group with one disulfide bond and one terminal alkynyl group,the microsphere could enrich azidelabeled glycopeptides,but this binding was interfered greatly by those organic groups with strong hydrophobicity.Our research group then introduced two ether groups into the hydrocarbon chain,resultantly increased hydrophilicity of the microsphere and decreased influence of nonglycosylated peptides on the enrichment process.The second part of our paper further explored the application of the reconstructed microsphere in the enrichment of azide-labeled O-GalNAc peptides,and finally found it able to specifically enrich azide-labeled O-GalNAc peptides from complex biological samples,which would provide important technical support for the study of O-GalNAc sites as well as the discovery of disease-related glycobiomarkers.