Method of producing and isolating igg-binding protein a fusion peptides

Abstract

A method of producing and selectively isolating a desired protein or polypeptide or derivative thereof by constructing a recombinant vector comprising a DNA sequence coding for said desired protein or polypeptide operatively linked to a DNA sequence coding for protein A or an active polypeptide fragment thereof or any other macromolecule capable of binding to the constant regions of immunoglobulins, such that said DNA sequences together code for an IgG-binding fusion product between said desired protein or polypeptide and said protein A, active polypeptide fragment thereof or macromolecule; transforming a compatible host with said recombinant vector such that the combined DNA sequences coding for said fusion protein or polypeptide can be expressed by the host, and culturing the transformed host in a suitable growth medium to produce said fusion protein or polypeptide; selectively isolating said fusion protein or polypeptide by adsorption to an IgG-supporting carrier material; and optionally desorbing said fusion protein or polypeptide from said IgG-supporting carrier, said fusion protein or polypeptide coded for by said combined DNA-sequence optionally comprising a unique cleavage site between said protein A part and said desired protein or polypeptide part, said desired protein or polypeptide part then being cleaved off from the rest of the fusion protein or polpeptide either while the latter is adsorbed to the IgG-supporting carrier or after desorption thereof from the carrier. Also a hybrid vector for use herein, a method and an expression vector for its preparation and a host organism transformed by said hybrid vector are disclosed.