Journal of Biotechnology & Biomaterials
Open Access

Abstract

Proteins are synthesized as precursors with additional N-terminal signal peptide. The signal peptide is cleaved off by signal peptidase once it has served its purpose of targeting the protein to and importing it into, the ER. Recently, recombinant DNA research has been used to study signal peptide and made it possible to show the efficiency activity of a proposed signal peptide by fusing it to another protein. In this study, signal peptide of human erythropoietin was replaced with the signal peptide of human IL-2, then the hydrophobic domain of the signal peptide was modified and its effect on the production of the target protein (erythropoietin) was evaluated. The nucleotide sequence of modified signal peptide was transported directly into the upstream of the 5ΓΆΒ?Β? end of the human erythropoietin gene by performing two rounds of amplification with pfu DNA polymerase. The gene of target protein with modified signal peptide was transiently expressed in animal cells and quantification of protein secretion was evaluated. As a result, extracellular levels of erythropoietin mediated by modified signal peptide were 4.5 and 1.9 fold higher than erythropoietin level mediated by native signal peptide. And, we also could observe significantly increased protein secretion up to 8 times high by modifying the wild-type human IL-2 signal peptide from HEK293A cells, in particular the hydrophobic domain. These findings indicate that increased hydrophobicity in their respective domain augments productivity of recombinant therapeutic proteins.

Biography

Email: djoh@sejong.ac.kr