Development of a robust, uniform, and magnetically orientable lipid mimetic will undoubtedly advance solid-state NMR of macroscopically aligned membrane proteins. Here, we report on a novel lipid membrane mimetic based on peptoid belts. The peptoids, composed of 15 residues, were synthesized by alternating N-(2-phenethyl)glycine with N-(2-carboxyethyl)glycine residues at a 2:1 molar ratio. The chemically synthesized peptoids possess a much lower degree of polydispersity versus styrene-maleic acid polymers, thus yielding uniform discs. Moreover, the peptoid oligomers are more flexible and do not require a specific folding, unlike lipoproteins, in order to wrap around the hydrophobic membrane core. The NMR spectra measured for the membrane-bound form of Pf1 coat protein incorporated in this new lipid mimetics demonstrate a higher order parameter and uniform linewidths compared with the conventional bicelles and peptide-based macrodiscs. Importantly, unlike bicelles, the peptoid-based macrodiscs are detergent free.

开发稳健、均匀且可磁性定向的脂质模拟物无疑将推动宏观排列膜蛋白的固态核磁共振技术的发展。在这里，我们报告了一种基于类肽带的新型脂质膜模拟物。这些类肽由 15 个残基组成，通过以 2:1 摩尔比交替N- (2-苯乙基)甘氨酸和N- (2-羧乙基)甘氨酸残基来合成。与苯乙烯-马来酸聚合物相比，化学合成的类肽具有低得多的多分散性，从而产生均匀的盘。此外，与脂蛋白不同，类肽寡聚体更加灵活，不需要特定的折叠来包裹疏水膜核心。与传统的 bicelles 和基于肽的宏圆盘相比，对这种新型脂质模拟物中掺入的 Pf1 外壳蛋白的膜结合形式测量的 NMR 光谱表明，其具有更高的阶参数和均匀的线宽。重要的是，与 bicelles 不同，基于类肽的宏光盘不含洗涤剂。