Biopanning of HGV epitope from a phage displayed library

Three mouse monoclonal antibodies (mAb) specific to E2 antigen of human hep atitis G virus (HGV) were used to bio-panning of a phage displayed random p eptide library of 15 amino acid residues. After 3 rounds of screening, the ratio of output to input increased to 1.1 x 10(-3) and the false positive r ate reduced to 0.2%, which means the enrichment was effective. At the third round of screening, 15 plage clones were selected for the use in binding a nd competitive inhibition tests. Thirteen of them could specifically react with the mAb M6. The inhibition rates of phage 10 clones out of 15 were ove r 60 %. From the deduced insert sequence in the coat protein WI, the core s equence NPLWP was found in 6 phage clones which are homologeous to the amin o acids 301-305 of HGV E2. The sera from the mice immunized with the phage clone C2 containing motif sequence were found positive for anti-HGV. These indicate the possibility that NPLWP motif in the short peptide is the mimic of HGV E2 epitope that can be recognized by HGV mAb M6.