An assay to determine the binding of a mutein with an IL-4Ralpha

摘要

An assay for determining the ability of a mutein to bind to a receptor, comprising steps of: (a) introducing into a scintillant-coated microplate with streptavidin the binding portion of a receptor chain which has a peptide tag capable of being bound by streptavidin; (b) introducing into the scintillant-coated microplate a radiolabelled native ligand having an affinity for the binding portion of the receptor chain; (c) introducing into the scintillant-coated microplate a mutein ligand having an affinity for the binding portion of the receptor chain; (d) measuring the amount of signal given off by the scintillant-coated microplate after allowing for equilibration; and (e) calculating the affinity of the mutein ligand versus the native ligand. The method preferably uses the receptor chain IL-4Rá.