Structural Characterization of a Minimal Antibody against Human APOBEC3B.
Structural Characterization of a Minimal Antibody against Human APOBEC3B.
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DOI：
10.3390/v13040663
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发表时间：
2021-04-12
期刊：
影响因子：
--
通讯作者：
Aihara H
中科院分区：
文献类型：
--
作者：
Tang H;Demir Ö;Kurniawan F;Brown WL;Shi K;Moeller NH;Carpenter MA;Belica C;Orellana K;Du G;LeBeau AM;Amaro RE;Harris RS;Aihara H
APOBEC3B （A3B）是七种人类APOBEC3 DNA胞嘧啶脱氨酶之一，作为整体先天免疫反应的一部分，它限制病毒感染，但它也通过突变基因组DNA在肿瘤进化中发挥重要作用。鉴于A3B作为病毒感染的限制因子和多种人类癌症的驱动因素的重要性，针对A3B的选择性抗体非常需要在各种研究和可能的诊断应用中进行特异性检测。在这里，我们描述了一种高亲和力的最小抗体，命名为5G7，通过针对A3B的c端催化结构域（ctd）的噬菌体展示筛选获得。5G7还结合与A3Bctd高度同源的APOBEC3A，但不结合另一种z1型脱氨酶结构域APOBEC3G的催化结构域。5G7的晶体结构显示出重链和轻链可变结构域的典型排列，它们的互补决定区（CDR）环排列在抗原结合间隙内，该间隙可容纳一对α-螺旋。为了了解5G7识别A3Bctd的机理，我们以A3Bctd和5G7的晶体结构为模板，计算预测了A3B-5G7的复合体结构。通过位点定向诱变和体外结合分析进一步验证了模拟得到的稳定结合姿态。这些研究将5G7的表位定位到A3Bctd的c端α6螺旋的一部分，其中Arg374发挥了重要作用。A3Bctd的相同区域以前被用作产生兔单克隆抗体（mAb 5210-87-13）的肽抗原，这表明该区域具有特别的免疫原性，并且这些来自不同来源的抗体可能具有相似的结合模式。我们的研究为开发针对A3B和其他APOBEC3家族酶的选择性抗体提供了一个平台。
APOBEC3B (A3B) is one of seven human APOBEC3 DNA cytosine deaminases that restrict viral infections as part of the overall innate immune response, but it also plays a major role in tumor evolution by mutating genomic DNA. Given the importance of A3B as a restriction factor of viral infections and as a driver of multiple human cancers, selective antibodies against A3B are highly desirable for its specific detection in various research and possibly diagnostic applications. Here, we describe a high-affinity minimal antibody, designated 5G7, obtained via a phage display screening against the C-terminal catalytic domain (ctd) of A3B. 5G7 also binds APOBEC3A that is highly homologous to A3Bctd but does not bind the catalytic domain of APOBEC3G, another Z1-type deaminase domain. The crystal structure of 5G7 shows a canonical arrangement of the heavy and light chain variable domains, with their complementarity-determining region (CDR) loops lining an antigen-binding cleft that accommodates a pair of α-helices. To understand the mechanism of A3Bctd recognition by 5G7, we used the crystal structures of A3Bctd and 5G7 as templates and computationally predicted the A3B-5G7 complex structure. Stable binding poses obtained by the simulation were further tested by site-directed mutagenesis and in vitro binding analyses. These studies mapped the epitope for 5G7 to a portion of C-terminal α6 helix of A3Bctd, with Arg374 playing an essential role. The same region of A3Bctd was used previously as a peptide antigen for generating a rabbit monoclonal antibody (mAb 5210-87-13), suggesting that this region is particularly immunogenic and that these antibodies from very different origins may share similar binding modes. Our studies provide a platform for the development of selective antibodies against A3B and other APOBEC3 family enzymes.
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影响因子：
14.8
作者：
Kozakov D;Hall DR;Xia B;Porter KA;Padhorny D;Yueh C;Beglov D;Vajda S
通讯作者：
Vajda S
DOI：
10.1002/pros.23656
发表时间：
2018-09
期刊：
The Prostate
影响因子：
--
作者：
Glumac PM;Forster CL;Zhou H;Murugan P;Gupta S;LeBeau AM
通讯作者：
LeBeau AM
影响因子：
4.8
作者：
Shi, Ke;Carpenter, Michael A.;Aihara, Hideki
通讯作者：
Aihara, Hideki
影响因子：
4.7
作者：
Hintz, Hallie M.;Cowan, Aidan E.;LeBeau, Aaron M.
通讯作者：
LeBeau, Aaron M.
影响因子：
2.2
作者：
Sommavilla, R.;Lovato, V.;Neri, D.
通讯作者：
Neri, D.