XL-MS (Cross-linking Mass Spectrometry)

This method is based on cross-linking of proteins with bi-functional reagents of specific length targeting specific protein residues and subsequent mass spectrometric detection of formed links. The result is a qualitative information about specific residue distances in individual proteins, or within multiple proteins. This technique can be used for identification and characterization of protein-protein interactions, or residue distances in individual proteins to aid structural modeling.

Contact person: František Filandr



O’Reilly, F.J., Rappsilber, J. Cross-linking mass spectrometry: methods and applications in structural, molecular and systems biology. Nat Struct Mol Biol 25, 1000–1008 (2018). https://doi.org/10.1038/s41594-018-0147-0

Requirements:

  •     Isolated protein or protein complexes in solution
  •     Sequence of protein(s) with information about existing PTMs
  •     Selection of cross-linking reagent after discussion with operator
  •     Suitable buffer for cross-linking reaction. Reagents based on NHS chemistry targeting lysines in proteins (DSBU, DSPU, DSSBU, DSS, BS3, DSSO) react with primary amines, which must not be present in the buffers
  •     Information about the exact composition of samples, including potential contaminants


Results:

  • List of unique cross-links between amino acid residues in analyzes proteins in .xlms or .csv formats
  • Schematic illustration of detected cross-links generated from xiView software in vector or bitmap format
  • Validation and visualization of detected cross-links on model protein structures using Xlink Analyzer (UCSF Chimera) in bitmap format, alongside an analysis of structural match between found cross-links and underlying model structure


Expected turnaround time:

  •     2 to 3 weeks