Resolution of a complex ionic mixture of an apparently homogenous protein preparation by preparative electrophoresis

Abstract

279-283Preparations of recombinant envelope glycoprotein E2 of hepatitis C virus (r-HCV E2), found to be homogeneous by N-terminal amino acid sequencing and mass spectrometry, resolved into multiple ionic species (isoforms) when analysed by isoelectric focusing (IEF) gel electrophoresis in the pI range of 3-10. These isoforms possessed pI &nbsp;values in the range or 4.5-8.2. The major isoform with p<i style="mso-bidi-font-style: normal">I value of approximately 7. 1 was separated from the rest of them by employing a method developed on Gradiflow BF 200, a device based on preparative electrophoresis. This isoform was adjudged to be homogenous by IEF and by native polyacrylamide gel electrophoresis (PAGE)