In situ studies of protein crystal growth by atomic force microscopy

Abstract

Atomic force microscopy was used to obtain images of lysozyme crystals growing in their native solution environment. The authors growth by both two-dimensional nucleation and screw dislocation mechanisms. Nucleation centres appeared to occur randomly over the surface, and were uncorrelated from layer to layer. Surface defects on the (110) face were found in the form of double-arm spirals, opposing pairs of such spirals, or more complex structures. The formation of defects as layers grew over foreign particles, and occasional later healing of the defects, were followed. At sufficiently low supersaturation, defect-mediated growth dominated over growth by two-dimensional nucleation.