One-step purification of a model periplasmic protein from inclusion bodies by its fusion to an effective metal-binding peptide.

It has been demonstrated that the addition of a metal-binding amino acid sequence to an exposed terminus of a protein can be useful for purification using immobilized metal affinity chromatography (IMAC). Polyhistidine extensions, wherein sequential histidyl residues are placed at the end of a protein, have been utilized for protein purification through IMAC. Natural metal-binding peptides may also serve as starting points for the design of an affinity tail. As a model system, an octapeptide derived from angiotensin I was fused to TEM-beta-lactamase. When the modified protein was expressed in Escherichia coli, a one-step purification of this recombinant protein was accomplished from resolubilized inclusion body material.