Analytical method and application of fragmentable chemical cross-linking agent based on glycosidic bond mass spectrometry

Abstract

The present invention relates to an analysis method based on glycosidic bond mass spectrometry fragmentable chemical cross-linking agent for analyzing protein-protein interaction by chemical cross-linking mass spectrometry. The chemical cross-linking reaction between the cross-linking agent and the protein complex is carried out, and the selective difference in the fragmentation energy of the glycosidic bond and the peptide bond is used to realize the highly selective and controllable fragmentation of the cross-linking reagent and the peptide bond of the cross-linked peptide, thereby Reduce the complexity of the spectrum of cross-linked peptides and significantly reduce the scale of data retrieval, realize the large-scale analysis of protein complexes based on chemical cross-linking strategies, and provide an important technology for studying the spatial structure of proteins and protein-protein interaction networks support.

Description

technical field [0001] The invention relates to an analysis method based on glycosidic bond mass spectrometry fragmentable chemical cross-linking agent, which utilizes the selective difference in fragmentation energy of glycosidic bond and peptide bond mass spectrometry to reduce the complexity of cross-linked peptide spectrum and significantly reduce data The scale of retrieval enables large-scale analysis of protein complexes based on chemical cross-linking strategies, providing important technical support for the study of protein spatial structures and protein-protein interaction networks. Background technique [0002] As the main executor of life activities in organisms, proteins form complex complexes through protein-protein interactions, thereby regulating various life activities in a precise and orderly manner. Fine analysis of protein complexes, mapping of protein conformational folding changes and interaction networks between proteins is of great importance for unde...

AI Technical Summary

Problems solved by technology

However, the above techniques have many limitations: Yeast two-hybrid technique can identify the direct interaction between two proteins, but it is not suitable for complex protein interaction network analysis in vivo, and there is a problem of false positive rate; co-immunoprecipitation technique Although it can identify interacting proteins in vivo, it cannot distinguish between direct and indirect interactions, and it is difficult to achieve effective identification for transient and weak interactions; protein crystallization combined with X-ray diffraction and nuclear magnetic resonance techniques and cryo-electron microscopy techniques can provide High-resolution structural information of protein complexes

However, the technology still faces many challenges

The most severe of these is the complexity of data analysis for cross-linked peptides

The secondary spectrum of an ordinary peptide involves only one peptide and fragmentation occurs only once, while the spectrum of a cross-linked peptide not only involves two peptides but also fragments in various forms, which may occur on any peptide or It may occur on the cross-linking agent, the fragment ions of its secondary spectrum are more in type and number than the conventional spectrum, and the database size it faces is the square level of ordinary database search, resulting in long search time, and For protein interaction information at the omics level, due to the very large database, it is not even possible to complete the identification

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