NATIVE PROTEIN PURIFICATION TECHNOLOGY

The present invention relates to an isolated polypeptide comprising (a) a protein of interest; (b) a first member of a pair of binding partners; (c) an affinity tag for immobilizing the polypeptide on a solid support; and (d) a modified endoprotease recognition site, wherein the modified endoprotease recognition site is located directly adjacent to the N-terminal amino acid of the protein of interest and comprises or only consists of the amino acid sequence N-terminal of the cleavage site of the native endoprotease recognition site. The present invention also relates to a nucleic acid encoding the above polypeptide and a host cell thereof, a method for isolating a protein of interest using the above polypeptide as a fusion partner and a protease fusion protein with the second member of the pair of binding partners and kits thereof. In addition, a method of degrading a target protein, a method of treatment and use of a fusion protease protein comprising a protease and a target protein binding element are also disclosed.