Contribution of Cross-linking and Ion-mobility for the study of protein and complex structures

The tridimensional structures of proteins and the mapping of protein-protein interactions are precious sources of information for the understanding of their function. Different techniques such as X-ray cristallography or nuclear magnetic resonance are usually used to achieve this goal. In the field of mass spectrometry, several tools were also developped. The one presented here is the chemical cross-linking in which two reactive residue side chains, spatially close, are linked thanks to a bifunctional chemical, called crosslinker.
Ion-mobility coupled to mass spectrometry has also been investigated for the study of cross-linked products. The first results tend to show that cross-linkers allow to fix the shape of the protein in solution, leaving it intact when analysed in the gas phase.