Methods to study protein dynamics and folding by mass spectrometry.

It is clear that merely knowing the structure of a protein alone is not sufficient to fully understand its behavior: knowledge also of the dynamic events that occur within proteins is vital to elucidate their function and folding. In recent years, mass spectrometry has come to the forefront as a powerful biophysical method, which can shed light both on the structure and dynamics of proteins. Hydrogen exchange monitored by mass spectrometry is a highly sensitive marker of the backbone dynamics in solution that, combined with gas phase dissociation techniques, can provide a high resolution tool to locate the dynamic regions of a protein. Additionally, charge state distributions in electrospray mass spectra yield insight into the nature and population of alternate structural states present at equilibrium. In this paper, we describe several applications of these methodologies to probe the dynamic events key to the structure, folding, and biological functions of proteins.