Protein glycosylation is a key protein post-translational modification that involves attaching a glycan group to a specific amino acid residue of a protein. Glycosylated proteins (glycoproteins) play a key role in a variety of processes in the cell, such as cell-cell interactions, cell signaling, and immune responses.
Figure 1Glycosylation modification research route.
1.Type of glycosylation
1.N-linked glycosylation: Usually occurs at the asparagine-n position in proteins. The specific sequence pattern is ASN-X-ser Thr (X can be any amino acid except proline). 2.O-Nexus Glycosylation: Typically occurs on tyrosine, serine, or threonine residues of proteins. 2.Methods of site analysis
1.Mass spectrometry: After the protein is digested, the protein fragment is analyzed by liquid chromatography mass spectrometry (LC-MS MS) to determine the location of the glycosylation site. 2.Radiolabeling: Proteins are labeled using radiolabeled sugar precursors, such as radiolabeled UDP-GLCNAC, and then separated by electrophoresis and detected by auto-imaging of the proteins. 3.Chemical labeling: The use of specific chemical reagents, such as eccentric acids, bind to glycosylation sites and detect them by mass spectrometry or other methods. 
Figure 2Case study of glycosylation modifications.
3.Fields of application
1.Biomarker research: In some diseases, such as diabetes, the pre-glycation end products (AGEs) formed by non-enzymatic mediated glycation modifications are closely related to disease progression and can be used as biomarkers of disease. 2.Drug development: Inhibition or enhancement of specific glycosylation sites may provide potential targets for the development of new drugs. 3.Disease mechanism studies: Glycosylation has been implicated in the onset and progression of many diseases, such as Alzheimer's disease, cancer, and arteriosclerosis.