Structure of a zosuquidar and UIC2-bound human-mouse chimeric ABCB1.
Structure of a zosuquidar and UIC2-bound human-mouse chimeric ABCB1.
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DOI：
10.1073/pnas.1717044115
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发表时间：
2018-02-27
影响因子：
11.1
通讯作者：
Locher KP
中科院分区：
文献类型：
--
作者：
Alam A;Küng R;Kowal J;McLeod RA;Tremp N;Broude EV;Roninson IB;Stahlberg H;Locher KP
ATP结合盒转运体ABCB1（也称为p糖蛋白）是生理上必需的多药物外排转运体，与生物医学有重要关系。在这里，我们报道了ABCB1与人类ABCB1特异性抑制抗体UIC2和第三代ABCB1抑制剂zosuquidar抗原结合片段复合物的构象捕获和结构分析。这些结构概述了抗体和小分子对ABCB1特异性抑制的关键特征，包括抑制剂在完全封闭的ABCB1腔中结合的双重模式。最后，我们的分析揭示了转运体达到抑制剂结合状态所经历的构象转变。多药转运体ABCB1 （p -糖蛋白）是一种atp结合盒转运体，在保护组织免受毒性损伤和促进多药挤出癌细胞方面发挥关键作用。在这里，我们报道了无核苷酸ABCB1的近原子分辨率低温电镜结构，该结构被核苷酸结合域（NBDs）之间的工程二硫交联所捕获，并与人类特异性抑制抗体UIC2的抗原结合片段和第三代ABCB1抑制剂zosuquidar结合。我们的结构揭示了转运蛋白的封闭构象，其中心有一个封闭的抑制剂结合口袋，由ABCB1的所有跨膜螺旋的残基排列。口袋几乎横跨整个脂质膜的宽度，并完全由两个密切相互作用的zosuquidar分子占据。促进UIC2结合的外部构象表位也被可视化，为其抑制底物外排提供了基础。额外的低温电镜结构表明，与关闭NBD间隙以及zosuquidar结合相关的转运蛋白的两半的TM螺旋协同运动。我们的研究结果确定了ABCB1抑制剂的不同识别界面，这可能用于治疗目的。
The ATP binding cassette transporter ABCB1 (also termed P-glycoprotein) is a physiologically essential multidrug efflux transporter of key relevance to biomedicine. Here, we report the conformational trapping and structural analysis of ABCB1 in complex with the antigen-binding fragment of UIC2, a human ABCB1-specific inhibitory antibody, and zosuquidar, a third-generation ABCB1 inhibitor. The structures outline key features underlining specific ABCB1 inhibition by antibodies and small molecules, including a dual mode of inhibitor binding in a fully occluded ABCB1 cavity. Finally, our analysis sheds light on the conformational transitions undergone by the transporter to reach the inhibitor-bound state. The multidrug transporter ABCB1 (P-glycoprotein) is an ATP-binding cassette transporter that has a key role in protecting tissues from toxic insult and contributes to multidrug extrusion from cancer cells. Here, we report the near-atomic resolution cryo-EM structure of nucleotide-free ABCB1 trapped by an engineered disulfide cross-link between the nucleotide-binding domains (NBDs) and bound to the antigen-binding fragment of the human-specific inhibitory antibody UIC2 and to the third-generation ABCB1 inhibitor zosuquidar. Our structure reveals the transporter in an occluded conformation with a central, enclosed, inhibitor-binding pocket lined by residues from all transmembrane (TM) helices of ABCB1. The pocket spans almost the entire width of the lipid membrane and is occupied exclusively by two closely interacting zosuquidar molecules. The external, conformational epitope facilitating UIC2 binding is also visualized, providing a basis for its inhibition of substrate efflux. Additional cryo-EM structures suggest concerted movement of TM helices from both halves of the transporters associated with closing the NBD gap, as well as zosuquidar binding. Our results define distinct recognition interfaces of ABCB1 inhibitory agents, which may be exploited for therapeutic purposes.
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影响因子：
5.8
作者：
Chufan EE;Kapoor K;Ambudkar SV
通讯作者：
Ambudkar SV
影响因子：
2.9
作者：
Druley, TE;Stein, WD;Roninson, IB
通讯作者：
Roninson, IB
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
DOI：
10.1126/science.1168750
发表时间：
2009-03-27
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Aller SG;Yu J;Ward A;Weng Y;Chittaboina S;Zhuo R;Harrell PM;Trinh YT;Zhang Q;Urbatsch IL;Chang G
通讯作者：
Chang G
影响因子：
64.8
作者：
Dawson, Roger J. P.;Locher, Kaspar P.
通讯作者：
Locher, Kaspar P.