Patent ID: 8163890

Claim:
A method for the production of a heterologous polypeptide of interest with a homogenous N-terminus, using a fusion polypeptide comprising the heterologous polypeptide of interest and N-terminally thereto a polypeptide exhibiting autoproteolytic function, said method comprising the steps of a) binding of the fusion polypeptide in a soluble, autoproteolytically inactive form by an affinity chromatography system, b) refolding of the fusion polypeptide, thereby activating the autoproteolytic function of the fusion polypeptide and causing cleavage of the heterologous polypeptide of interest, and c) subsequently eluting the heterologous polypeptide of interest, wherein said steps are conducted on one affinity chromatography system, wherein said method utilizes an oligopeptide ligand selected from the group consisting of: SEQ ID NO 6: VSIFEW, SEQ ID NO 7: AVSIEWY, SEQ ID NO 8: AVSFIWY, SEQ ID NO 9: VSFIWYK, SEQ ID NO 10: ASRFWYA, SEQ ID NO 11: AFYTWYA, SEQ ID NO 12: AFYRWYK, SEQ ID NO 13: AFYRWY, SEQ ID NO 14: AFYRWYA, SEQ ID NO 15: AVSIFEWY, SEQ ID NO 16: AVSRNWY, SEQ ID NO 17: ASRFWY, SEQ ID NO 18: AFYRWYAA, SEQ ID NO 19: AFYRWY, SEQ ID NO 20: ASRFWYAA, SEQ ID NO 21: AFYRWYAA and SEQ ID NO 22: AFYSWYAA, which selectively binds to the part of the fusion polypeptide exerting autoproteolytic function under chaotropic conditions.