In Vivo Cross-Linking to Analyze Transient Protein-Protein Interactions

Cross-linking converts noncovalent interactions between proteins into covalent bonds. The now artificially fused molecules are stable during purification steps (e.g., immunoprecipitation). In combination with a variety of techniques, including Western blotting, mass spectrometry (MS), and bioinformatics, this technology provides improved opportunities for modelling structural details of functional complexes in living cells and protein-protein interaction networks. The presented strategy of immunoaffinity purification and mass spectrometry (AP-MS) coupled with in vivo cross-linking can easily be adapted as a robust workflow in interactome analyses of various species, also nonmodel organisms.