PLASMID PGEX-5T - AN ALTERNATIVE SYSTEM FOR EXPRESSION AND PURIFICATION OF RECOMBINANT PROTEINS

A novel expression vector pGEX-5T was constructed which directs the synthesis of a fusion protein with a histidine-hexapeptide and glutathione-S-transferase at its N-terminus and the recombinant protein at its C-terminus in Escherichia coli. The designed fusion gene strategy allows the purification of soluble and insoluble recombinant proteins to homogeneity with single-step affinity chromatography using immobilized glutathione and metal chelating matrix, respectively. The principle and availability of this new expression system was respectively tested with the purification of a soluble and insoluble recombinant fusion protein containing 24 and 75 amino acids of the human thrombomodulin.