Abstract
Diffracted X-ray Tracking (DXT) is one of single molecule techniques for investigating intra-molecule dynamics of functional proteins. In DXT, a nanocrystal is immobilized on a target protein and the trajectory of its diffracted spot is analyzed as the motion of the protein. We advanced the time resolution of this method and refined the analysis procedures in the last 5 years, and the method has been useful especially for cooperative motion analysis in multimeric proteins. In this article, we review the characteristic features and recent progress of DXT.