Production and characterization of a fusion peptide derived from the rabies virus glycoprotein (RVG29)

• We have expressed a fusion peptide (RVG29-9R-6His).
• We have assessed the physiochemical properties of the RVG29-9R-6His peptide.
• We found that the RVG29-9R-6His peptide specifically recognizes Neuro 2a cells.
• RVG29-9R-6His may provide a novel, economical, strategy for brain-targeted delivery.

Gene therapy targeting the brain holds great promise in curing nervous system degenerative diseases in clinical applications. With this in mind, in a previous study a 29 amino-acid peptide derived from the rabies virus glycoprotein (RVG29) with a nonamer stretch of arginine residues (RVG29-9R) at its carboxy-terminus was exploited as a ligand for brain-targeting gene delivery. Importantly, the report demonstrated that the RVG29-9R vector was able to cross the blood–brain barrier. RVG29-9R is currently synthesized by commercial companies with high associated costs. In this study, in order to reduce the costs of producing RVG29-9R, we have expressed and purified 6 mg of a recombinant peptide (RVG29-9R-6His) from 0.4 g of cultured Escherichia coli. We assessed the physiochemical properties of RVG29-9R-6His, its cytotoxicity, and the in vitro transfection efficiency in Neuro 2a cells (which express the acetylcholine receptor). Our results reveal that the RVG29-9R-6His peptide recognized Neuro 2a cells in a dose-dependent manner and it was also able to bind plasmid DNA and deliver it into the Neuro 2a cells effectively. Therefore, our study has demonstrated that the recombinant RVG29-9R-6His peptide retains the functions of RVG29-9R and so may provide an economically viable and alternative production method for the manufacture of RVG29-9R.