Use of Marker Ions and High Resolution Precursor Ion Scan for the Identification of Cross-linked Peptides

摘要

The fragmentation study reveals the presence of marker ions for all peptides. The marker ions are specific for different cross-linked species (dead-end, intra- and intermolecular). The marker ions are present for all three NHS-based cross-linkers used. The mass of marker ions does not match any regular b or y ion. Precursor Ion Scans (PIS) can be performed to identify cross-linked peptides. The marker ions are very specific for cross-linked peptide if high resolution is used for PIS experiments.