Structural analysis of proteins using X-ray diffraction technique

Proteins are the most amazing group of molecules, playing a vital role in biological system, and are considered as important components of body tissues, enzymes, antibodies, etc. Modern-day biochemistry and molecular biology emphasize a main focus on understanding the relation between structural properties and functions of biological macromolecules. As a consequence, structural characterization techniques at molecular level have gained tremendous popularity over the years. X-ray diffraction (XRD) is a powerful analytical and nondestructive technique widely used for structural determination of crystalline materials by chemists. Protein crystallography is the study of the three-dimensional structures of proteins at near atomic resolution. It has provided marvelous insight into the workings of numerous biological processes over the last few decades. This chapter gives an overview of the XRD technique, working principle, instrumentation, and its utility in the structural characterization of protein. Additionally, suitable examples along with experimental data demonstrating the application of XRD technique for structural evaluation studies are discussed in detail.