Solubility studies of a viral proteins

Abstract

Hepatitis B virus (HBV) infects many people world-wide. An X protein (HBx) is produced during the virus replication and in order to study its role in the progression of the virus, a regular continuous supply of pure bioactive HBx proteins is required. Presently, when HBx is produced recombinantly, they form inclusion bodies and this leads to very poor yields of bioactive HBx proteins. The current strategy to produce sufficient amounts of HBx proteins for characterization studies is to solubilize and refold the inclusion body-derived HBx proteins. However, the yield of the refolded HBx protein is currently low because of a kinetic competition between aggregation and refolding. The objective in this project was to conduct a literature review investigation into dilution and on-column refolding techniques base on published HBx refolding studies. An investigation on the kinetic competition between aggregation and refolding was carried as well. The results of the investigations showed that there was little correlation between the yield of refolded HBx proteins and the refolding method used. Despite the lack of reliable kinetic data on HBx refolding, the model was able to predict generally a high yield of refolded proteins at low concentrations of denatured proteins. As a result, improvements to the current methods of refolding are required to scale-up the refolding process to provide a regular continuous supply of pure bioactive HBx proteins.