OPTIMIZED RELEASE OF RECOMBINANT PROTEINS BY ULTRASONICATION OF ESCHERICHIA-COLI-CELLS

The release kinetics of beta-galactosidase protein have been determine d during small-scale ultrasonication of E. coli cells. Among several s tudied parameters, ionic strength and cell concentration have the leas t influence on the rate of protein recovery, whereas sample volume and acoustic power dramatically affect the final yield of soluble protein in the cell-free fraction. The analysis of these critical parameters has prompted us to propose a simple model for E. coli disintegration t hat only involves acoustic power and sample volume, and which allows p rediction of optimal sonication times to recover significant amounts o f both natural and recombinant proteins in a given set of relevant con ditions. (C) 1998 John Wiley & Sons, Inc.