Protein release from Escherichia coli cells permeabilized with guanidine–HCl and Triton X100

Abstract An important factor complicating the recovery of recombinant proteins from Escherichia coli is their intracellular location. An alternative to the commonly used method of releasing these proteins by mechanical disruption is to chemically permeabilize the cells. The objective of this research was to characterize the protein release kinetics of a permeabilization process using guanidine–HCl and Triton X100. The protein release rate and yield were determined as a function of the guanidine and Triton concentrations. The initial release rate increased monotonically with increasing concentrations of Triton and guanidine whereas the release yield varied in a complex manner. Electron microscopy indicated that the permeabilization process involves a solubilization of the inner membrane and molecular alteration of the outer wall. Some advantages of this process over mechanical disruption include avoiding extensive fragmentation of the cells and retainment of nucleic acids inside the cell structure.