Martinez Denis, Decossas Marion, Kowal Julia, Frey Lukas, Stahlberg Henning, Dufourc Erick J, Riek Roland, Habenstein Birgit, Bibow Stefan, Loquet Antoine
CBMN, CNRS., University of Bordeaux, IECB, All. Geoffroy Saint-Hilaire, 34600, Pessac, France.
D C-CINA, University of Basel, 4058, Basel, Switzerland.
Chemphyschem. 2017 Oct 6;18(19):2651-2657. doi: 10.1002/cphc.201700450. Epub 2017 Jun 30.
Nanodiscs offer a very promising tool to incorporate membrane proteins into native-like lipid bilayers and an alternative to liposomes to maintain protein functions and protein-lipid interactions in a soluble nanoscale object. The activity of the incorporated membrane protein appears to be correlated to its dynamics in the lipid bilayer and by protein-lipid interactions. These two parameters depend on the lipid internal dynamics surrounded by the lipid-encircling discoidal scaffold protein that might differ from more unrestricted lipid bilayers observed in vesicles or cellular extracts. A solid-state NMR spectroscopy investigation of lipid internal dynamics and thermotropism in nanodiscs is reported. The gel-to-fluid phase transition is almost abolished for nanodiscs, which maintain lipid fluid properties for a large temperature range. The addition of cholesterol allows fine-tuning of the internal bilayer dynamics by increasing chain ordering. Increased site-specific order parameters along the acyl chain reflect a higher internal ordering in nanodiscs compared with liposomes at room temperature; this is induced by the scaffold protein, which restricts lipid diffusion in the nanodisc area.
纳米圆盘为将膜蛋白整合到类天然脂质双层中提供了一种非常有前景的工具,并且是脂质体的一种替代物,可在可溶性纳米级物体中维持蛋白质功能和蛋白质 - 脂质相互作用。掺入的膜蛋白的活性似乎与其在脂质双层中的动力学以及蛋白质 - 脂质相互作用相关。这两个参数取决于被脂质环绕的盘状支架蛋白所包围的脂质内部动力学,这可能与在囊泡或细胞提取物中观察到的更无限制的脂质双层不同。本文报道了对纳米圆盘中脂质内部动力学和热致性的固态核磁共振光谱研究。纳米圆盘几乎消除了凝胶 - 流体相转变,在很大的温度范围内保持脂质流体性质。添加胆固醇可通过增加链有序性来微调内部双层动力学。与室温下的脂质体相比,沿酰基链增加的位点特异性序参数反映了纳米圆盘中更高的内部有序性;这是由支架蛋白诱导的,它限制了纳米圆盘区域内脂质的扩散。