Mass spectrometry method for complete glycosylated peptide fragment based on quasi-multistage spectrum

Abstract

The invention relates to a mass spectrometry method for a complete glycosylated peptide fragment based on quasi-multistage spectrum and an application thereof in early diagnosis of liver cancer. The method mainly comprises the following five steps: 1) enrichment of a glycosylated peptide fragment; 2) sample preparation of a deglycosylated peptide fragment-complete glycosylated peptide fragment; 3)mass spectrometry of the deglycosylated peptide fragment-complete glycosylated peptide fragment; 4) spectrogram data retrieval of the deglycosylated peptide fragment-complete glycosylated peptide fragment; and 5) based on the above, through combination of glycosylation site and complete glycopeptide quantification technology, realizing glycosylation refined difference analysis of a cancer patientand a normal person and screening potential disease markers. The method realizes refined analysis of human protein glycosylation, and has important application potential in screening the tumor markers.

Description

technical field [0001] The invention belongs to the technical field of glycosylation proteomics in the research direction of proteomics, and specifically relates to the high-throughput identification and quantitative analysis of N-linked glycosylated peptides, and the application of the technology in clinical diagnosis of tumors. Background technique [0002] As the most common and important post-translational modification, protein glycosylation is involved in immune response, cell-cell interaction, ligand-receptor interaction and other processes, and its abnormality is closely related to the occurrence of diseases. At present, most of the protein tumor markers used clinically are glycosylated proteins, such as the marker protein of liver cancer - alpha-fetoprotein (AFP), the marker of malignant tumor - cancer antigen 125 (cancer antigen 125), and the marker of prostate cancer Substances-prostate cancer specific antigen (PSA) etc. However, the current tumor markers mainly f...

AI Technical Summary

Problems solved by technology

This method achieves the simultaneous fragmentation of sugar chains and peptide backbones, but it is difficult to simultaneously screen ions for further fragmentation due to the impact of ion transport efficiency

The above difficulties lead to limited glycopeptide analysis throughput, sensitivity and identification efficiency of MS2-MS3 strategy

Therefore, it is still a major challenge to achieve accurate analysis of glycosylated peptides

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