Hepatitis C virus core protein production and purification in a baculovirus expression system for biological assays.

Abstract

Background. The hepatitis C virus (HCV) commonly causes persistent infection. One of the viral mechanisms in preventing viral clearance is the ability of HCV to induce functional alterations of the immune system cells, specifically of dendritic cells. Viral proteins producing the dendritic cell functional alterations have been identified as the HCV core protein, which makes up the capsid structural unit.
Objective. One of the limitations to evaluate core protein properties is the difficulty in obtaining and purifying the complete protein--consisting of 191 amino acids. The aim of the current study was to produce and purify the recombinant core protein in a eukaryotic system, and to evaluate its effect in human dendritic cell cultures.
Results. The core protein p23 isoform was expressed in a baculovirus system and purified using isoelectric point separation and electroelution. The purity of the core protein was confirmed by silver stain and Western blot. These analyses showed the presence of two bands that correspond to p23 and p21 isoforms of core protein as previously reported.
Conclusion. The expressed protein differed from naive core protein is terms of molecular weight, isoforms and subcellular localization. The procedures developed for core protein are applicable for expression of other membrane-associated proteins produced in eukaryotic systems.