50] Identification of interferon receptors by chemical cross-linking

Abstract

This chapter discusses the identification of interferon receptors by chemical cross-linking. Interferon (IFN) action is apparently mediated through an interaction with receptors on the cell surface. Studies on IFN receptors have been carried out during recent years with the use of purified natural and recombinant IFNs. Mouse and human IFNs bind to specific receptors on cells with high affinity. The receptors for human IFNs (Hu-IFNs) (α, β, and γ) have been identified by chemical cross-linking. A conventional way to study cellular receptors is by measuring the binding of radiolabeled ligand, (IFN in this case) which is displaceable by an excess of the same but unlabeled ligand. This is a measure of specific binding sites. The total number of receptors, and the dissociation constant of this binding can be estimated by measuring specific displaceable binding at increasing concentrations of the radiolabeled IFN and analysis of the data by Scatchard plot. The cross-linked complex obtained, as described in the chapter, can be cleaved if a cleavable cross-linking reagent is used.