An enhanced protein crosslink identification strategy using CID-cleavable chemical crosslinkers and LC/MSn analysis

作者：Liu Fan; Wu Cong; Sweedler Jonathan V; Goshe Michael B^*

来源：Proteomics, 2012, 12(3): 401-405.

DOI：10.1002/pmic.201100352

• CID-cleavable crosslinker
• Crosslinking
• Mass measurement accuracy
• Multistage CID
• Protein-protein interactions
• Technology

We describe a novel two-step LC/MSn strategy to effectively and confidently identify numerous crosslinked peptides from complex mixtures. This method incorporates the use of our gas-phase cleavable crosslinking reagent, disuccinimidyl-succinamyl-aspartyl-proline (SuDP), and a new data-processing algorithm CXLinkS (Cleavable Crosslink Selection), which enables unequivocal crosslink peptide selection and identification on the basis of mass measurement accuracy, high resolving power, and the unique fragmentation pattern of each crosslinked peptide. We demonstrate our approach with well-characterized monomeric and multimeric protein systems with and without database searching restrictions where inter-peptide crosslink identification is increased 8-fold over our previously published data-dependent LC/MS3 method and discuss its applicability to other CID-cleavable crosslinkers and more complex protein systems.

• 出版日期2012-2