Abstract
A review is given on the crystal growth of hen egg-white lysozyme. The history, principle, and technique of protein crystal growth are first briefly described. It is then shown that the crystal growth of lysozyme is similar to that of lower molecular weight substances in that (1) the crystal solubility (Cs) can experimentally be determined, (2) a variation of Cs can be represented in phase diagrams, and (3) both the size and the period needed for the appearance of crystals (D) are largely determined by the degree of supersaturation. However, lysozyme crystal growth is characteristic in that (1) polymorphism depending on pH, counterion, and temperature is observed, (2) the number of tetragonal crystals increases on reducing the degree of supersaturation below a certain value, leading to smaller crystal size, and (3) both D and the crystal growth rate are much longer than those usually observed for smaller substances.
