Numerical studies on the pre-nucleation transport in the liquid/liquid diffusion crystallization of proteins

The numerical simulation method is used to study the solute transport in a real case of protein crystallization with the liquid/liquid diffusion method. The results of the study show that the ratio of the volumes of protein and salt solutions in a growth tube of constant diameter, plus the salt concentration in the protein solution are the principal causes of the spatial and temporal distributions of supersaturation, which may in turn affect the nucleation region and the number of nuclei. The concentrations of protein and salt solutions have small influence on the distributions of supersaturation, and they mainly influence the maximum of supersaturation. These dependencies could be used to optimize the crystallization conditions in order to develop the advantages of the liquid/liquid diffusion method. (C) 1998 Published by Elsevier Science B.V. All rights reserved.