Detection of molecular interactions by using a new peptide-displaying bacteriophage biosensor

Foreign peptides fused to the carboxy terminus of P22 tailspike protein are solvent-exposed and highly antigenic when displayed on the surface of infe ctious virus particles. Binding of an anti-peptide specific Fab antibody fr agment enhances the infectivity of chimeric bacteriophage particles in a ti tre-dependent fashion. Although the precise molecular basis of this enhance d infectivity remains unclear, experimental data and modelling approaches s uggest that the antibody binding might restore conformational impairments i n the assembled tail protein affecting its activity and performance during infection. These results suggest that in addition to free enzymes, peptide- displaying bacteriophages could be engineered as new biosensors to detect m olecular interactions by using natural viral enzymes critical for cell infe ction, (C) 1999 Academic Press.