Molecular Biophysics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany.
Department of Chemistry, University of Ibadan, 200284, Ibadan, Nigeria.
Angew Chem Int Ed Engl. 2017 Feb 6;56(7):1919-1924. doi: 10.1002/anie.201610778. Epub 2017 Jan 12.
Once removed from their natural environment, membrane proteins depend on membrane-mimetic systems to retain their native structures and functions. To this end, lipid-bilayer nanodiscs that are bounded by scaffold proteins or amphiphilic polymers such as styrene/maleic acid (SMA) copolymers have been introduced as alternatives to detergent micelles and liposomes for in vitro membrane-protein research. Herein, we show that an alternating diisobutylene/maleic acid (DIBMA) copolymer shows equal performance to SMA in solubilizing phospholipids, stabilizes an integral membrane enzyme in functional bilayer nanodiscs, and extracts proteins of various sizes directly from cellular membranes. Unlike aromatic SMA, aliphatic DIBMA has only a mild effect on lipid acyl-chain order, does not interfere with optical spectroscopy in the far-UV range, and does not precipitate in the presence of low millimolar concentrations of divalent cations.
一旦从其自然环境中移除，膜蛋白就依赖于膜模拟系统来保留其天然结构和功能。为此，已经引入了由支架蛋白或两亲聚合物（如苯乙烯/马来酸（SMA）共聚物）组成的脂质双层纳米盘作为替代去污剂胶束和脂质体用于体外膜蛋白研究。在这里，我们表明，交替的二异丁烯/马来酸（DIBMA）共聚物在溶解磷脂方面与 SMA 表现出同等的性能，稳定了功能性双层纳米盘中的完整膜酶，并直接从细胞膜中提取各种大小的蛋白质。与芳香族 SMA 不同，脂肪族 DIBMA 对脂质酰基链有序性的影响仅轻微，在远紫外范围内不干扰光学光谱，并且在存在低毫摩尔浓度的二价阳离子时不沉淀。
