Marconnet Anaïs, Michon Baptiste, Le Bon Christel, Giusti Fabrice, Tribet Christophe, Zoonens Manuela
Université de Paris, Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, UMR 7099, F-75005 Paris, France.
Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, F-75005 Paris, France.
Biomacromolecules. 2020 Aug 10;21(8):3459-3467. doi: 10.1021/acs.biomac.0c00929. Epub 2020 Jul 23.
Membrane proteins (MPs) need to be extracted from biological membranes and purified in their native state for most structural and functional in vitro investigations. Amphiphilic copolymers, such as amphipols (APols), have emerged as very useful alternatives to detergents for keeping MPs water-soluble under their native form. However, classical APols, such as poly(acrylic acid) (PAA) derivatives, seldom enable direct MP extraction. Poly(styrene maleic anhydride) copolymers (SMAs), which bear aromatic rings as hydrophobic side groups, have been reported to be more effective extracting agents. In order to test the hypothesis of the role of cyclic hydrophobic moieties in membrane solubilization by copolymers, we have prepared PAA derivatives comprising cyclic rather than linear aliphatic side groups (CyclAPols). As references, APol A8-35, SMAs, and diisobutylene maleic acid (DIBMA) were compared with CyclAPols. Using as models the plasma membrane of and the extraction-resistant purple membrane from , we show that CyclAPols combine the extraction efficiency of SMAs with the stabilization afforded to MPs by classical APols such as A8-35.
对于大多数体外结构和功能研究而言，膜蛋白（MPs）需要从生物膜中提取并以其天然状态进行纯化。两亲性共聚物，如两性分子（APols），已成为替代洗涤剂的非常有用的选择，可使MPs在其天然形式下保持水溶性。然而，经典的APols，如聚丙烯酸（PAA）衍生物，很少能直接提取MPs。据报道，带有芳香环作为疏水侧基的聚（苯乙烯马来酸酐）共聚物（SMAs）是更有效的提取剂。为了验证环状疏水部分在共聚物溶解膜过程中作用的假设，我们制备了包含环状而非线性脂肪族侧基的PAA衍生物（环状APols）。作为对照，将APol A8 - 35、SMAs和二异丁烯马来酸（DIBMA）与环状APols进行了比较。以[具体生物]的质膜和[具体生物]的抗提取紫膜为模型，我们表明环状APols兼具SMAs的提取效率和经典APols（如A8 - 35）给予MPs的稳定性。
