Isotope-coded and affinity-tagged cross-linking (ICATXL): an efficient strategy to probe protein interaction surfaces.

Academic Article


  • Chemical cross-linking followed by identification of the cross-linked residues by mass spectrometry provides structural information on protein interaction surfaces. Nevertheless, accurate analysis of the digested, cross-linked proteins is often challenging. Herein, we describe a novel strategy that relies on the use of affinity-tagged cross-linkers and isotope coding on the cross-linker-modified species. Incorporation of O16 or O18 during the hydrolysis of the cross-linkers results in a characteristic "doublet" for the undesired products of a half-cross-linking reaction. Therefore, genuine cross-linked peptides are readily distinguished for further structural analysis. This strategy permits a sensitive and facile analysis on a dimeric protease inhibitor, ecotin, showing general applicability to other protein assemblies.
  • Authors

  • Chu, Feixia
  • Mahrus, Sami
  • Craik, Charles S
  • Burlingame, Alma L
  • Status

    Publication Date

  • August 16, 2006
  • Keywords

  • Affinity Labels
  • Cross-Linking Reagents
  • Crystallography, X-Ray
  • Escherichia coli Proteins
  • Isotope Labeling
  • Models, Molecular
  • Molecular Structure
  • Periplasmic Proteins
  • Proteins
  • Surface Properties
  • Digital Object Identifier (doi)

    Pubmed Id

  • 16895390
  • Start Page

  • 10362
  • End Page

  • 10363
  • Volume

  • 128
  • Issue

  • 32