[Expression, purification and identification of human IFN-alpha 2 b/HBV Pre S2 fusion protein].
OBJECTIVE
To express a fusion protein of human interferon-a2b and HBV Pre S2 in E.coli for the purpose of investigating anti-HBV immunomodulatory protein.


METHODS
Human interferon-a2b and HBV Pre S2 encoding genes were amplified from plasmid templates through PCR, then fused and cloned into plasmid pBV220 through engineering technique to generate expression plasmid pBV-IFN-Pre S2. The plasmid was transfected into E. coli to produce fusion protein. RP-HPLC and ion-exchange chromatography were employed to purify fusion protein.


RESULTS
27 kDa fusion protein was expressed up to 15% of total bacterial protein in E. coli. After purification, the purity of fusion protein reached 95% of total protein. Anti-viral assay showed that IFN-Pre S2 protein induced a VSV-resistant activity of 1.25 x 10(8) lU/mg protein in Wish cell line, similar to the bioactivity of original recombinant human IFN-alpha 2b. ELISA data showed that IFN-Pre S2 protein had antigenicities of both human IFN-alpha 2b and HBV Pre S2. In addition, fusion protein showed the feature of binding to polymeric human serum albumin (PHSA).


CONCLUSIONS
The bifunctional fusion protein was efficiently expressed in E. coli. The work provided initial evidence for studying PHSA-receptor-targeting IFN-alpha 2b,which might have potential application for the treatment of HBV infection.
Xu
D
D
Department of Biological Engineering, 302 Hospital of PLA, Beijing 100039, China.
Han
F
F
Shi
H
H
D000595:Amino Acid Sequence; D019677:Artificial Gene Fusion; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006514:Hepatitis B Surface Antigens / Q000096:biosynthesis* / Q000235:genetics; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification*; D011994:Recombinant Proteins
D006514:Hepatitis B Surface Antigens; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C050807:presurface protein 2, hepatitis B surface antigen