Published online Jul 14, 2005. doi: 10.3748/wjg.v11.i26.4018
Revised: July 11, 2004
Accepted: July 11, 2004
Published online: July 14, 2005
AIM: To construct a random peptide phage display library and search for peptides that specifically bind to the PreS region of hepatitis B virus (HBV).
METHODS: A phage display vector, pFuse8, based on the gene 8 product (pVIII) of M13 phage was made and used to construct a random peptide library. E.coli derived thioredoxin-PreS was purified with Thio-bond beads, and exploited as the bait protein for library screening. Five rounds of bio-panning were performed. The PreS-binding specificities of enriched phages were characterized with phage ELISA assay.
RESULTS: A phage display vector was successfully constructed as demonstrated to present a pVIII fused HBV PreS1 epitope on the phage surface with a high efficiency. A cysteine confined random peptide library was constructed containing independent clones exceeding 5±108 clone forming unit (CFU). A pool of phages showing a PreS-binding specificity was obtained after the screening against thio-PreS with an enrichment of approximately 400 times. Five phages with high PreS-binding specificities were selected and characterized. Sequences of the peptides displayed on these phages were determined.
CONCLUSION: A phage library has been constructed, with random peptides displaying as pVIII-fusion proteins. Specific PreS-binding peptides have been obtained, which may be useful for developing antivirals against HBV infection.