Conformational dynamics of single protein molecules studied by direct mechanical manipulation

Advances in single-molecule manipulation techniques have recently enabled researchers to study a growing array of biological processes in unprecedented detail. Individual molecules can now be manipulated with subnanometer precision along a simple and well-defined reaction coordinate, the molecular end-to-end distance, and their conformational changes can be monitored in real time with ever-improving time resolution. The behavior of biomolecules under tension continues to unravel at an accelerated pace and often in combination with computational studies that reveal the atomistic details of the process under investigation. In this chapter, we explain the basic principles of force spectroscopy techniques, with a focus on optical tweezers, and describe some of the theoretical models used to analyze and interpret single-molecule manipulation data. We then highlight some recent and exciting results that have emerged from this research field on protein folding and protein-ligand interactions.