Reverse-phase liquid chromatography (RPLC) in Combination with Tip-Based Strong Cation Exchange (SCX-Tip) Fractionation, ReST, an Alternative Approach for Cross-linked Peptides analysis

ABSTRACT: Chemical cross-linking in combination with mass spectrometry (XL-MS) has emerged as a useful method for structural elucidation of proteins and protein complexes. Efficient enrichment procedures are necessary to analyze cross-linked products due to their relatively low abundance. Currently, strong cation exchange chromatography (SCX), size exclusion chromatography (SEC), and affinity tag-based enrichment are among the widely used enrichment strategies. Herein, we present a two-dimensional enrichment strategy combining basic RPLC (bRPLC) fractionation and tip-based SCX (SCX-Tip) enrichment, termed ReST method, for the characterization of cross-linked peptides. We revealed the unbiased separation effects of the bRPLC in the cross-linked peptide fractionation. We optimized the enrichment conditions of SCX-Tip for cross-linked peptides using well-designed cross-linked peptides. Taking advantage of the high resolution of bRPLC fractionation and the high enrichment efficiency of SCX-Tip, we were able to identify 43.6% more cross-links than the conventional SCX approach. The presented ReST approach is an effective fractionation method for XL-MS analysis, and could be beneficial for protoeme-scale protein-protein interaction studies. Moreover, more stringent data filtering was proposed in order to achieve the high confidence of cross-linked peptide identification.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Zhen Wu  

LAB HEAD: Xumin Zhang

PROVIDER: PXD023817 | Pride | 2022-06-16

REPOSITORIES: Pride