Introduction: Hepatitis C Virus (HCV)
is one of the leading causes of chronic hepatitis and hepatocellular
carcinoma. Given the side effects of the current treatment, novel anti-viral
therapies are highly needed to combat viral hepatitis and minimize the
adverse effects. Phage display is a powerful technique for selecting random
peptides fused to bacteriophage surface proteins from a library of different
sequences. These peptide libraries are screened for specific binding to
target proteins. Sequencing of the selected phage genome is used to determine
the 12-mer peptide presented on the phage.
Aim: The study aims to develop and
improve phage selection experiments and identify peptides capable of high
affinity binding to HCV E2 glycoprotein. Biopanning using a variety of random
peptide phage display libraries, and assessing their potential to inhibit HCV
entry was performed.
Results: Several conditions were tested
and normalised using two model proteins for phage binding assay, bovine serum
albumin (BSA) as a control protein and an anti-pIII antibody as a positive
coating material. More than forty phage clones were selected and sequenced
after several biopanning experiments performed under several conditions.
Selected phage peptides from the optimized biopanning specifically
neutralised entry of HCV retroviral pseudoparticles (P <0.05) but not on
vesicular stomatitis virus (VSV). After sequencing selected peptide encoding
region, multiple sequence alignment tools such as ClustalW and Biology
Workbench have shown consensus residues among these peptides.
Conclusion: The biopanning technique
seems to be affected by a myriad of factors. We have investigated and
resolved some of the interfering factors for more specific results. These
results suggest that optimized phage display technology might be a successful
approach to select specific peptide inhibitors to HCV infection. Further
studies are underway to synthesize the lead peptides for more inhibition
studies, and also assess possible synergy with other peptides and