DNA-based selection and screening of peptide ligands.

Abstract

Phage display selection strategies rely on the physical link between the displayed heterologous protein ligand and the DNA encoding it. Thus, genes expressing a ligand with a specific binding affinity can be selected rapidly. To improve the specificity and sensitivity of this technology for potential use in identifying ligands to a specific antibody present in a complex mixture, we incorporated a DNA selection step along with the phage display technology. Ligands for hepatitis C virus (HCV) antibodies present in serum were identified by panning a phage-displayed random peptide library against pools of serum HCV antibodies. An additional DNA hybridization screening step using single-stranded DNA isolated from one of the pools increased the specificity and sensitivity, resulting in the selection of an HCV antibody ligand with diagnostic potential.