Mitochondrial ADP/ATP Carrier in Dodecylphosphocholine Binds Cardiolipins with Non-native Affinity
Mitochondrial ADP/ATP Carrier in Dodecylphosphocholine Binds Cardiolipins with Non-native Affinity
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DOI：
10.1016/j.bpj.2017.09.019
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发表时间：
2017-12-05
影响因子：
3.4
通讯作者：
Chipot, Christophe
中科院分区：
文献类型：
--
作者：
Dehez, Francois;Schanda, Paul;Chipot, Christophe
膜蛋白的生物物理研究通常需要使用去污剂从天然来源中提取它们，这一步骤可能导致蛋白质变性，可能是不可逆的。十二烷基磷酸胆碱（DPC），一种广泛用于膜蛋白NMR研究的去污剂，扭曲其结构的倾向一直是备受争议的话题。最近有人提出，酵母线粒体ADP/ ATP载体（yAAC 3）对心磷脂的结合特异性被保留在DPC中，从而表明DPC是研究膜蛋白的合适环境。在本通讯中，我们使用全原子分子动力学模拟来研究心磷脂与yAAC 3的特异性结合。我们的数据表明，在一个本地样的环境中观察到的相互作用界面显着不同，从DPC的NMR调查推断，这意味着在这种洗涤剂，蛋白质结构是扭曲的。我们进一步研究了yAAC 3溶解在DPC和温和的十二烷基麦芽糖苷与热位移测定。在DPC中观察到的热转变的损失证实了蛋白质在该环境中不再正确折叠。
Biophysical investigation of membrane proteins generally requires their extraction from native sources using detergents, a step that can lead, possibly irreversibly, to protein denaturation. The propensity of dodecylphosphocholine (DPC), a detergent widely utilized in NMR studies of membrane proteins, to distort their structure has been the subject of much controversy. It has been recently proposed that the binding specificity of the yeast mitochondrial ADP/ ATP carrier (yAAC3) toward cardiolipins is preserved in DPC, thereby suggesting that DPC is a suitable environment in which to study membrane proteins. In this communication, we used all-atom molecular dynamics simulations to investigate the specific binding of cardiolipins to yAAC3. Our data demonstrate that the interaction interface observed in a native-like environment differs markedly from that inferred from an NMR investigation in DPC, implying that in this detergent, the protein structure is distorted. We further investigated yAAC3 solubilized in DPC and in the milder dodecylmaltoside with thermal-shift assays. The loss of thermal transition observed in DPC confirms that the protein is no longer properly folded in this environment.