CrosslinkingMS

Crosslinking Mass Spectrometry, often abbreviated as XL-MS, is an analytical technique used to study the three-dimensional structure of proteins and protein complexes. It involves chemically attaching crosslinking reagents to amino acid residues that are in close proximity within a folded protein or interacting proteins. These reagents have reactive groups at either end and a spacer arm of a defined length. Following the crosslinking reaction, the protein or complex is digested into smaller peptides. The crosslinked peptides, which contain the attached crosslinker, are then identified and quantified using mass spectrometry. By analyzing the mass-to-charge ratio of these crosslinked peptides and their fragmentation patterns, researchers can infer which amino acids were in close proximity, thereby providing information about the protein's structure and interaction interfaces. XL-MS is a powerful tool for mapping protein surfaces, characterizing protein-protein interactions, and investigating conformational changes. It can be applied to both isolated proteins and proteins within complex biological environments, offering insights into dynamic biological processes. The specificity of the crosslinking reagent and the sensitivity of mass spectrometry are key factors in the success of this technique.