THE THREE DIMENSIONAL STRUCTURES OF PROTEINS

The general nature of the problem of molecular structure in protein chemistry is discussed. As in all of organic chemistry, this problem has two aspects: the determination of the structural formula (a province of classical organic chemistry) and the determination of the molecular conformation. Recent progress in both of these areas has been great. Information on the amino acid sequences in proteins is rapidly accumulating (essentially a problem which concerns the structural formulae of proteins). Detailed knowledge of the conformations of proteins in general, and recently of myoglobin and hemoglobin in particular, has come from various kinds of x-ray crystallographic studies. Other physical tools (especially optical rotatory power and ultraviolet spectroscopy) give less detailed but still highly useful information about molecular conformation. The current state of our knowledge of the nature of the forces responsible for the molecular conformations of proteins is briefly reviewed.