We study biomolecular interactions, structure, and dynamics, with the aim of understanding biological systems and processes at the molecular level. The emphasis is on experimental and theoretical studies of the physical properties of proteins in solution: their folding, assembly, and stability; their 3D structures and conformational dynamics; their interactions with water, ions, and other solvent components and their electrostatic interactions with ligands and other biomolecules. Our principal experimental method is nuclear magnetic resonance (NMR). We are also active in the development of NMR theory and methodology. Other experimental methods used in our work include optical spectroscopies and the tools of protein chemistry and molecular biology.