Université d'Avignon et des Pays de Vaucluse, Equipe Chimie Bioorganique et Systèmes Amphiphiles, Avignon, France.
Langmuir. 2012 Mar 13;28(10):4625-39. doi: 10.1021/la205026r. Epub 2012 Feb 29.
A novel type of nonionic amphipols for handling membrane proteins in detergent-free aqueous solutions has been obtained through free-radical homo-telomerization of an acrylamide-based monomer comprising a C(11) alkyl chain and two glucose moieties, using a thiol as transfer reagent. By controlling the thiol/monomer ratio, the number-average molecular weight of the polymers was varied from 8 to 63 kDa. Homopolymeric nonionic amphipols were found to be highly soluble in water and to self-organize, within a large concentration range, into small, compact particles of ~6 nm diameter with a narrow size distribution, regardless of the molecular weight of the polymer. They proved able to trap and stabilize two test membrane proteins, bacteriorhodopsin from Halobium salinarum and the outer membrane protein X of Escherichia coli, under the form of small and well-defined complexes, whose size, composition, and shape were studied by aqueous size-exclusion chromatography, analytical ultracentrifugation, and small-angle neutron scattering. As shown in a companion paper, nonionic amphipols can be used for membrane protein folding, cell-free synthesis, and solution NMR studies (Bazzacco et al. 2012, Biochemistry, DOI: 10.1021/bi201862v).
通过自由基均聚反应，用巯基作为转移试剂，合成了一种新型的非离子两亲聚合物，用于处理无胶束去污剂水溶液中的膜蛋白。该两亲聚合物由包含 C(11) 烷基链和两个葡萄糖单元的丙烯酰胺单体组成。通过控制巯基/单体的比例，可以改变聚合物的数均分子量，范围从 8 到 63 kDa。均聚物非离子两亲聚合物在水中具有很高的溶解性，并在很大的浓度范围内自组装成直径约 6nm 的小而紧凑的颗粒，且颗粒尺寸分布较窄，而与聚合物的分子量无关。它们能够以小而明确的复合物的形式捕获和稳定两种测试膜蛋白，来自盐杆菌的菌紫质和大肠杆菌的外膜蛋白 X，其大小、组成和形状通过水相尺寸排阻色谱、分析超速离心和小角中子散射进行了研究。正如一篇相关论文所述，非离子两亲聚合物可用于膜蛋白折叠、无细胞合成和溶液 NMR 研究（Bazzacco 等人，2012 年，生物化学，DOI：10.1021/bi201862v）。
