Chemical cross‐linking and mass spectrometry for mapping three‐dimensional structures of proteins and protein complexes

Chemical cross‐linking of proteins, an established method in protein chemistry, has gained renewed interest in combination with mass spectrometric analysis of the reaction products for elucidating low‐resolution three‐dimensional protein structures and interacting sequences in protein complexes. The identification of the large number of cross‐linking sites from the complex mixtures generated by chemical cross‐linking, however, remains a challenging task. This review describes the most popular cross‐linking reagents for protein structure analysis and gives an overview of the strategies employing intra‐ or intermolecular chemical cross‐linking and mass spectrometry. The various approaches described in the literature to facilitate detection of cross‐linking products and also computer software for data analysis are reviewed. Cross‐linking techniques combined with mass spectrometry and bioinformatic methods have the potential to provide the basis for an efficient structural characterization of proteins and protein complexes. Copyright © 2003 John Wiley & Sons, Ltd.