Liptáková H, Kontseková E, Alcamí A, Smith G L, Kontsek P
Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia.
Virology. 1997 May 26;232(1):86-90. doi: 10.1006/viro.1997.8527.
The soluble B18R protein coded by vaccinia virus exerts properties of a type I interferon (IFN)-receptor with broad species specificity. We analyzed neutralizing and binding activity of the B18R protein against several recombinant human type I IFNs. The B18R protein inhibited the antiviral potency of IFN-alpha1, IFN-alpha2, IFN-alpha8/1/8, and IFN-omega on human cells. The N-terminal domain of human type I IFN is involved in the high affinity binding to its cellular receptor. To localize the binding domain(s) of IFN with the B18R protein, competition experiments between B18R, and mapped monoclonal antibodies to IFN-alpha1 and IFN-alpha2 were performed. Surprisingly, our data indicated that the contact area between the B18R protein and IFN comprised in addition to the N-terminal region of IFN-molecule also its C-terminal portion. We suggest that this different pattern of interaction with a ligand might determine the ability of B18R protein to bind type I IFNs of different species.
痘苗病毒编码的可溶性B18R蛋白具有I型干扰素（IFN）受体的特性，具有广泛的物种特异性。我们分析了B18R蛋白对几种重组人I型干扰素的中和及结合活性。B18R蛋白抑制了IFN-α1、IFN-α2、IFN-α8/1/8和IFN-ω对人细胞的抗病毒效力。人I型干扰素的N端结构域参与其与细胞受体的高亲和力结合。为了定位干扰素与B18R蛋白的结合结构域，进行了B18R与针对IFN-α1和IFN-α2的定位单克隆抗体之间的竞争实验。令人惊讶的是，我们的数据表明，B18R蛋白与干扰素之间的接触区域除了包括干扰素分子的N端区域外，还包括其C端部分。我们认为，这种与配体不同的相互作用模式可能决定了B18R蛋白结合不同物种I型干扰素的能力。
