Investigation of protein-ligand interactions by mass spectrometry.

The rate of drug discovery is greatly dependent on the development and improvement of rapid and reliable analytical methods that allow screening for protein-ligand interactions. The solution-based methods for investigating protein-ligand interactions by mass spectrometry (MS), which are discussed in this paper, are hydrogen/deuterium exchange of protein backbone amide hydrogens, and photoaffinity labeling. Moreover, MS analysis of intact noncovalent protein-ligand complexes is described. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) with its ultra-high resolution and excellent mass accuracy is also considered herein as it is gaining increasing popularity for a mass spectrometric investigation of protein-ligand interactions.