Codon optimization to improve the production yield of recombinant human interferon α by Pichia pastoris

Abstract

In this work we employ PEGylated polyethyleneimine (pPEI) o act both as an affinity ligand, to increase the selectivity of the ystem, and as a pDNA condensation agent. In this way we were ble to obtain plasmid polyplexes with a 100% yield without NA or protein contamination, after two ATPS extractions from lkaline lysates. In the first one a PEG 600—ammonium sulhate system, already described, was used and in the second one t was employed a PEG 3350—Dextran 110 system containing PEI. The isolation of polyplexes was carried out by ultrafiltraion. Although a substantial removal of Dextran and PEG was chieved the yield in polyplexes was very low (5–10%). This as due to binding of the polyplexes to the polyethersulphone embrane used. Further studies are being carried to optimize he ultrafiltration step. These results open the possibility of simultaneously purifyng and condensing the plasmid with the delivery vehicle for herapeutic applications and achieving the integration of two mportant steps on pharmaceutical plasmids production.