Pres1 Activity Of Hepatitis B Virus Structural Domain Peptide Segments

The PreS1 region of hepatitis B virus surface antigen contains different biology activity and high antigenicity. The gene encoding the N-terminal 65 amino acid residents of preS 1 was amplified by PCR , which was directly inserted into the expression vector pGEX 4T-1 between EcoRI and BamHI sites and under the control of tac promoter The fused GST-PreS1(1-65) gene can be expressed in E.coli by IPTG induction . The expression level was up to more than 20% and in soluble form. Then it was fermented in NBS BIOFLO 3000 type autocontrolled fermentor and led to the result of approximately 50g wet recombinant E coli per liter as well as 1.2g fused protein per liter. The purity fusion protein was specially cleaved by thrombin digest to release the res1 peptide. The purity, integrity, and immunogenicity of the purified pres1 peptide was confirmed by glycerol-SDS-PAGE, western analysis, HPLC, mass spectroscopy, N-terminal amino acid sequencing and an indirect ELISA.To utilize the affinity of The preS1 region of hepatitis B virus surface antigen binding to liver cell and the antitumor activity of TNF, The gene encoding The N-terminal 65 amino acid residents of PreS1 which contains B and T cell epitopes and hepatocyte receptor binding site. was amplified by PCR and fused to the 3' end of hTNF α gene to form a hTNFα -PreS1 fused gene which was directly inserted into the expression vector pSB-92 between EcoRI and BamHI sites and under the control of P₁ promoter The fused hTNF α -...