FLUOR - Fluorinated Surfactants for Membrane-Protein Research

膜蛋白在细胞通讯和转运过程中发挥着重要作用，并代表了大多数药物靶点。尽管如此，我们对膜蛋白结构、动力学和功能的认识和理解进展缓慢，主要是因为它们非常疏水的性质带来的困难。这些蛋白质需要一个膜模拟环境，以保持它们在体外研究过程中既可溶又有活性，这通常是在去污剂、溶解膜蛋白和脂质的表面活性化合物的帮助下完成的。然而，许多膜蛋白在溶解于洗涤剂中时失活，即它们失去其天然结构和功能。这促使人们努力用温和的替代品取代传统的洗涤剂，其中氟化表面活性剂似乎特别有前途。由于碳氟化合物对碳氢化合物的亲和力较弱以及碳氟化合物的体积较大，氟化表面活性剂被假设为不太不稳定，因为它们几乎不与蛋白质-蛋白质和蛋白质-脂质/疏水辅因子相互作用竞争。事实上，已经反复证明，与氢化洗涤剂相比，溶解在氟化表面活性剂中的各种膜蛋白更稳定，然而，不幸的是，中性氟化表面活性剂不能溶解脂质双层并直接从膜中提取膜蛋白。因此，传统的洗涤剂仍然需要溶解，氟化表面活性剂只在后期发挥作用，此时不稳定的蛋白质已经受到不可逆的损伤。我们最近已经证明，由于氟化辛基麦芽糖苷衍生物保留了温和的洗涤剂样活性，因此脱乙酰基本身并不排除洗涤剂。在这个项目中，我们打算利用这一发现来开发、测试和建立氟化洗涤剂，其（i）可以以足够的量和纯度合成以广泛用于膜蛋白研究;（ii）显示有利的胶束性质，例如小的和明确的尺寸;（iii）以快速的、化学控制的方式分配到膜中、跨膜移位和溶解膜;（iv）以快速的、化学控制的方式溶解膜。（iv）直接从天然或合成膜中溶解膜蛋白，而不需要更苛刻的氢化去污剂;和（v）为这些蛋白质提供稳定化环境，该环境在延长的时间段内保持它们的天然结构和功能。这种氟化洗涤剂将打开新的可能性，在体外研究的生理和生物有趣的膜蛋白，迄今为止，逃避详细的determination.This高度跨学科的项目将在一个财团内完成，是唯一有资格解决合成，物理化学，生物物理，生物化学，和结构生物学方面的一致好评。

Membrane proteins play numerous vital roles in cellular communication and transport processes and represent the majority of drug targets. Still, progress in our knowledge and understanding of membrane-protein structure, dynamics, and function is slow, primarily because of difficulties arising from their very hydrophobic nature. These proteins require a membrane-mimetic environment to keep them both soluble and active during in vitro investigations, which is typically accomplished with the aid of detergents, surface-active compounds that solubilise membrane proteins and lipids. However, many membrane proteins are inactivated when solubilised in detergents, that is, they lose their native structures and functions. This has motivated many efforts at replacing conventional detergents by milder alternatives, among which fluorinated surfactants appear particularly promising. Owing to the weak affinity of fluorocarbons for hydrocarbons and to the larger volume of fluorocarbons, fluorinated surfactants are hypothesised to be less destabilising because they hardly compete with protein-protein and protein-lipid/hydrophobic cofactor interactions. Indeed, it has been shown repeatedly that various membrane proteins are more stable when solubilised in fluorinated surfactants as compared with hydrogenated detergents.Unfortunately, though, neutral fluorinated surfactants are not able to solubilise lipid bilayers and extract membrane proteins directly from membranes. Hence, conventional detergents are still required for solubilisation, and fluorinated surfactants come into play only at a later stage, when labile proteins will already have suffered irreversible damage. We have recently demonstrated that fluorination per se does not exclude detergency, as a fluorinated octyl maltoside derivative retains mild detergent-like activity. In this project, we intend to capitalise on this finding to develop, test, and establish fluorinated detergents that (i) can be synthesised in sufficient quantities and purities for widespread use in membrane-protein research; (ii) display favourable micellar properties such as small and well-defined sizes; (iii) partition into, translocate across, and solubilise membranes in a rapid, thermodynamically controlled manner; (iv) solubilise membrane proteins directly from native or synthetic membranes without requiring harsher, hydrogenated detergents; and (v) offer these proteins a stabilising environment that preserves their native structures and functions for extended periods of time. Such fluorinated detergents will open new possibilities for in vitro studies of physiologically and pharmacologically interesting membrane proteins that have thus far evaded detailed scrutiny.This highly interdisciplinary project shall be accomplished within a consortium that is uniquely qualified to address synthetic, physicochemical, biophysical, biochemical, and structural-biological aspects alike.