Recovery of soluble protein after expression in Escherichia coli depends on cellular disruption conditions.

Proteins overproduced in Escherichia coli are frequently recovered from bacterial extracts as insoluble material. The influence of different cell disruption procedures on the recovery of soluble protein, after recombinant protein expression in E. coli, was assessed using two beta-tubulin derivatives. Nonionic detergents such as Triton X-100 and Nonidet P-40 promote aggregation when present in the lysis buffer. The effect of Triton X-100 is reversed by the addition of 1 M NaCl in the lysis buffer indicating that the recombinant protein aggregation is probably caused by interactions with membrane proteins. The importance of the cellular disruption method on the recovery of potentially soluble recombinant proteins is discussed.