Receptor phage

Abstract
In this paper we demonstrate that phage display technology is a suitable system for studying the interaction between the high-affinity receptor for IgE (FcϵRI) and IgE. The α subunit extracellular domains of the human receptor were expressed on the surface of filamentous phage M 13 fused to the carboxyl-terminal part of the gene III protein (pIII). Two constructs were made, the first with both the Ig-like domains of the receptor α chain and the second with only the C-terminal domain. The fusion genes were cloned in a phagemid vector to display monovalently the receptor on the phage surface. Our results indicate that the α receptor expressed on the phage is able to interact with IgE as demonstrated by an ELISA assay. In addition, by using the same system, we show that a single domain of the α receptor is sufficient for the interaction with IgE although with a binding affinity lower than that of the two-domain receptor