Method for identifying glycoprotein sugar chain structure by combining two-dimensional gel electrophoresis and mass spectrometry

The invention discloses a method for identifying a glycoprotein sugar chain structure by combining two-dimensional gel electrophoresis and mass spectrometry. The method comprises the following steps:S1, performing specific enrichment on glycoprotein in a biological sample, performing separation through two-dimensional gel electrophoresis, and selecting target glycoprotein isomer gel spots according to the molecular weight and isoelectric point of target glycoprotein; S2, confirming the selected target glycoprotein isomer gel spots by using a two-dimensional gel electrophoresis western blot and a mass spectrum; and S3, performing intra-gel enzymolysis and mass spectrometry on the target glycoprotein isomer gel spots confirmed in the step S2, and identifying the peptide fragment sequence and the sugar chain structure. The method is suitable for separation and structural identification of isomers and modifiers of various protein post-translational modified (glycosylated, ubiquitinated, acetylated and the like) biomarkers, and can significantly improve the sensitivity and specificity of the post-translational modified protein as a diagnostic marker.