Preparation and characterization of biotinylated probes for the beta-interferon receptor

1. Recently we described the isolation of the beta-interferon receptor [Zhang et al. (1986) J. biol. Chem. 261, 8017-8021]. A highly purified product was obtained but in low quantities. 2. The use of biotinylated beta-interferon as a ligand represents an alternate approach to receptor isolation. 3. We have prepared and characterized the derivatives N-(biotinyl)- and N-(biotinyl-epsilon-aminocaproyl)-recombinant human [Ser17]-interferon beta (B- and BC-recHuIFN beta). 4. Biotin incorporation does not result in any loss of antiviral activity, demonstrating the recognition of the derivative by the cell receptor. 5. The biotinylated recHuIFN beta binds specifically and reversibly to succinoylavidin or guanidine thiocyanate-stripped succinoylavidin linked to a Sepharose matrix. 6. Comparison of the competition curves obtained with [14C]biotin and [3H]biotinyl recHuIFN, in the presence of increasing concentrations of biotin suggests that the IFN moiety of the derivative has little effect on the affinity of biotin for avidin. 7. Biotinylated recHuIFN beta derivatives represent useful probes for the beta-IFN receptor.