Sulfonated Amphipols: Synthesis, Properties, and Applications
Sulfonated Amphipols: Synthesis, Properties, and Applications
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DOI：
10.1002/bip.21683
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发表时间：
2011-12-01
期刊：
影响因子：
2.9
通讯作者：
Popot, Jean-Luc
中科院分区：
文献类型：
--
作者：
Dahmane, Tassadite;Giusti, Fabrice;Popot, Jean-Luc
Amphipols（APols）是保持膜蛋白（MP）水溶性的两亲聚合物。迄今为止，最好表征和最广泛使用的APol A8-35包含接枝有辛基和异丙胺侧链的聚丙烯酸酯主链。其亲水性部分的性质阻止其在微酸性pH下使用，这对于减缓溶液NMR研究中酰胺质子交换速率是理想的。我们在这里描述了通过用牛磺酸取代异丙基获得的pH不敏感APOL的合成和性质。磺化APols（SAPos）可用于捕获MP中的小复合物的形式，以稳定它们，并保持它们的水溶性，即使在低pH值。[N-15，H-1]-横向弛豫优化光谱NMR光谱在pH 6.8的细菌外MP折叠在SAPos显示，蛋白质是正确的折叠。光谱具有与A8-35所实现的分辨率相似的分辨率，并且揭示了在pH 8.0下不存在共振峰的水暴露的酰胺和吲哚质子。(C)2011 Wiley Periodicals，Inc. Biopolymers 95：811-823，2011.
Amphipols (APols) are amphiphatic polymers that keep membrane proteins (MPs) water-soluble. The best characterized and most widely used APol to date, A8-35, comprises a polyacrylate backbone grafted with octyl-and isopropylamine side chains. The nature of its hydrophilic moieties prevents its use at the slightly acidic pH that is desirable to slow down the rate of amide proton exchange in solution NMR studies. We describe here the synthesis and properties of pH-insensitive APols obtained by replacing isopropyles with taurine. Sulfonated APols (SAPols) can be used to trap MPs in the form of small complexes, to stabilize them, and to keep them water-soluble even at low pH. [N-15,H-1]-transverse relaxation-optimized spectroscopy NMR spectra obtained at pH 6.8 of a bacterial outer MP folded in SAPols show that the protein is correctly folded. The spectra have a resolution similar to that achieved with A8-35 and reveal water-exposed amide and indole protons whose resonance peaks are absent at pH 8.0. (C) 2011 Wiley Periodicals, Inc. Biopolymers 95: 811-823, 2011.