CONSTRUCTION OF AN IGG BINDING PROTEIN TO FACILITATE DOWNSTREAM PROCESSING USING PROTEIN ENGINEERING

摘要

A recombinant DNA fragment (Z) coding for an immunoglobulin G binding domain related to staphylococcal protein A. The methionine codon of the recombinant DNA fragment has been replaced with a codon of an amino acid residue other than methionine to enable expression of a methionine-free protein. The present invention is also directed to recombinant DNA sequence containing such recombinant DNAS fragment (Z) as well as a recombinant DNA molecule, plasmid vector and bacterial cell containing such recombinant DNAS fragment. Also disclosed is a process for cleaving a fused protein expressed in a biological system using said recombinant DNA fragment.