Disclosed is a method for the production of a heterologous polypeptide of interest with a homogenous N-terminus, using a fusion polypeptide comprising the 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.
