AN ALTERNATIVE FOR PURIFICATION OF LOW SOLUBLE RECOMBINANT HEPATITIS-C VIRUS CORE PROTEIN - PREPARATIVE 2-DIMENSIONAL ELECTROPHORESIS

For isolation of low soluble recombinant full-length (amino acids 1-19 1) core protein of hepatitis C virus (HCV) overexpressed in Escherichi a coil, the advantage of combining two electrophoretic techniques, in comparison with chromatographic separation, is demonstrated. The prote in extract was first solubilized in agents compatible with electrophor etic separation. Using preparative liquid phase isoelectric focusing ( IEF) the protein of interest was first concentrated within a defined a cidic pH range. These fractions were then submitted to preparative sod ium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) to isolate the 22 kDa protein. The second-dimensional step allowed the i solation of 2 mg of the purified recombinant HCV core protein (rHCV-C1 91) from 1.5 g bacterial pellet. This quantity is sufficient to charac terize the protein and to perform immunogenicity studies. This procedu re of two-dimensional preparative electrophoresis is applicable to a w ide range of biological samples and represents an alternative for puri fication of insoluble proteins.