Thermodynamic signatures of the antigen binding site of mAb 447-52D targeting the third variable region of HIV-1 gp120.
Thermodynamic signatures of the antigen binding site of mAb 447-52D targeting the third variable region of HIV-1 gp120.
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DOI：
10.1021/bi400645e
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发表时间：
2013-09-10
期刊：
影响因子：
2.9
通讯作者：
Kong, Xiang-Peng
中科院分区：
文献类型：
--
作者：
Killikelly, April;Zhang, Hui-Tang;Spurrier, Brett;Williams, Constance;Gorny, Miroslaw K.;Zolla-Pazner, Susan;Kong, Xiang-Peng
HIV-1 gp 120的第三可变区（V3）在病毒进入宿主细胞中起关键作用，因此，它是疫苗设计的潜在靶点。人单克隆抗体（mAb）447- 52 D是最广泛和有效中和抗V3 mAb之一。我们进一步通过确定与环状V3复合的Fab片段的高分辨率晶体结构来表征447- 52 D表位，并通过位点特异性诱变、等温滴定量热法（ITC）和中和测定的组合来询问抗原-抗体相互作用。我们发现447- 52 D的中和能力与其结合亲和力相关，在25 °C下，吉布斯自由结合能由大的热力学分量和小的有利熵分量组成。大的疏水贡献归因于（i）广泛的氢键网络，（ii）包围V3冠顶残基Arg 315的π-阳离子，和（iii）447- 52 D重链残基AspH 95和Arg 315之间的盐桥。Arg 315通常由进化枝B病毒携带;因此，我们的数据解释了为什么447- 52 D优先中和进化枝B病毒。在抗原结合界面的残基的热力学特征的询问提供了关键的见解，他们在抗原-抗体相互作用的贡献。
The third variable region (V3) of HIV-1 gp120 plays a key role in viral entry into host cells; thus, it is a potential target for vaccine design. Human monoclonal antibody (mAb) 447–52D is one of the most broadly and potently neutralizing anti-V3 mAbs. We further characterized the 447–52D epitope by determining a high-resolution crystal structure of the Fab fragment in complex with a cyclic V3 and interrogated the antigen–antibody interaction by a combination of site-specific mutagenesis, isothermal titration calorimetry (ITC) and neutralization assays. We found that 447–52D’s neutralization capability is correlated with its binding affinity and at 25 °C the Gibbs free binding energy is composed of a large enthalpic component and a small favorable entropic component. The large enthalpic contribution is due to (i) an extensive hydrogen bond network, (ii) a π–cation sandwiching the V3 crown apex residue Arg315, and (iii) a salt bridge between the 447–52D heavy chain residue AspH95 and Arg315. Arg315 is often harbored by clade B viruses; thus, our data explained why 447–52D preferentially neutralizes clade B viruses. Interrogation of the thermodynamic signatures of residues at the antigen binding interface gives key insights into their contributions in the antigen–antibody interaction.
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影响因子：
3.7
作者：
Gorny, Miroslaw K.;Pan, Ruimin;Zolla-Pazner, Susan
通讯作者：
Zolla-Pazner, Susan
影响因子：
64.8
作者：
Deng, HK;Liu, R;Landau, NR
通讯作者：
Landau, NR
影响因子：
3
作者：
Grosdidier S;Fernández-Recio J
通讯作者：
Fernández-Recio J
影响因子：
1.9
作者：
Li L;Zhao B;Cui Z;Gan J;Sakharkar MK;Kangueane P
通讯作者：
Kangueane P
DOI：
10.1107/s0907444908013978
发表时间：
2008-07-01
影响因子：
2.2
作者：
Dhillon, Amandeep K.;Stanfield, Robyn L.;Wilson, Ian A.
通讯作者：
Wilson, Ian A.