Chemical Cross-linking and Mass Spectrometry for the Structural Analysis of Protein Assemblies

Cellular functions are performed and regulated at a molecular level by the coordinated action of intricate protein assemblies, and hence the study of protein folding, structure, and interactions is vital to the appreciation and understanding of complex biological problems. In the past decade, continued development of chemical cross-linking methodologies combined with mass spectrometry has seen this approach develop to enable detailed structural information to be elucidated for protein assemblies often intractable by traditional structural biology methods. In this review article, we describe recent advances in reagent design, cross-linking protocols, mass spectrometric analysis, and incorporation of cross-linking constraints into structural models, which are contributing to overcoming the intrinsic challenges of the cross-linking method. We also highlight pioneering applications of chemical cross-linking mass spectrometry approaches to the study of structure and function of protein assemblies.