Two-dimensional crystallization of streptavidin: in pursuit of the molecular origins of structure, morphology, and thermodynamics

The streptavidin two-dimensional (2D) crystallization model has served as a paradigm for molecular self-assembly at interfaces. We have developed quan titative Brewster angle microscopy for the in situ measurement of spatially resolved relative protein surface densities. This allows investigation of both the thermodynamics and morphologies of 2D crystal growth. For crystal structure analysis, we employ TEM on grown crystals transferred to solid su bstrates. Comparison of results between commercially available streptavidin , recombinant streptavidin, and site-directed streptavidin mutants has prov ided insight into the protein-protein and protein-lipid interactions that u nderlie 2D crystallization. (C) 1999 Published by Elsevier Science B.V. All rights reserved.