Michelson interferometric studies of protein and virus crystal growth

In situ laser Michelson interferometry was utilized to investigate the growth kinetics and surface morphology in canavalin, thaumatin, and turnip yellow mosaic virus (TYMV) crystallization. Interferometric patterns and kinetic measurements from growing macromolecular crystals as small as 20 μm were obtained. This study shows that for the crystallization of canavalin, dislocations are the sources of growth steps on the surfaces of growing crystals. Supersaturation dependencies of the normal growth rates, tangential growth step velocities, and the slopes of the dislocation hillocks were determined. The kinetic coefficient β was estimated for canavalin grown from two different precipitant systems to be 3.2 × 10−4 and 5.3 × 10−4 cm s−1, respectively. The change in activities of dislocation sources under different growth conditions was analyzed.