Localization of the receptor binding site of IFN-alpha 2b.
The receptor binding site of IFN-alpha is not precisely known. To further characterize this site, mAb against IFN-alpha 2b were selected that block the binding of radiolabeled IFN-alpha 2b to its cell surface receptor. These antibodies also neutralized the anti-viral and anti-proliferative properties of IFN-alpha 2b. A subset of these antibodies (group 1) do not recognize IFN-alpha 2a, either in solid-phase immunoassays or functional assays, whereas a second subset (group 2), with no cross-reactivity with group 1, recognizes both IFN-alpha subtypes. Because IFN-alpha 2b and IFN-alpha 2a differ by only alpha Arg23-Lys23 substitution, group 1 antibodies must recognize an epitope within the receptor binding region of IFN-alpha 2b that includes Arg23. Group 2 antibodies recognize a separate and distinct epitope within the binding site that does not include Arg23.
Siemers
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R
Division of Medical Oncology, Lineberger Cancer Research Center, Chapel Hill, NC 27599.
Hensley
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L
Ozer
H
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000502:physiology; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D002460:Cell Line; D003429:Cross Reactions; D005260:Female; D006131:Growth Inhibitors / Q000494:pharmacology; D007140:Immunoglobulin Fab Fragments / Q000502:physiology; D007370:Interferon Type I / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D011863:Radioimmunoassay; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*; D017471:Receptors, Interferon
D000911:Antibodies, Monoclonal; D006131:Growth Inhibitors; D007140:Immunoglobulin Fab Fragments; D007370:Interferon Type I; D011971:Receptors, Immunologic; D017471:Receptors, Interferon