X-Ray Diffraction Studies of Crystalline Amino Acids, Peptides and Proteins

Three previous reviews have appeared in this Series describing the use of X-ray diffraction methods for the investigation of molecular structure: one by Kratky and Mark (4) on proteins and other natural products, one by COREY(I) on amino acids and peptides, and one by Pauling and Corey (II) on the configuration of polypeptide chains. During the 14 years that have passed since the last of these reviews, great progress has been made in X-ray diffraction techniques. As a result of these improved techniques, much more accurate and reliable data are now available concerning the dimensions of small biological molecules; in addition, detailed information concerning the structure of vastly more complex molecules is now being obtained. Whereas in 1954 structural information concerning proteins had to be deduced from knowledge of the structures of, at best, simple dipeptides, today such information is being obtained directly from crystalline proteins themselves.