FLUOR - Fluorinated Surfactants for Membrane-Protein Research

FLUOR - 用于膜蛋白研究的氟化表面活性剂

• 批准号: 316675121
• 负责人: Professor Dr. Sandro Keller
• 金额: --
• 依托单位: Institut für Molekulare Biowissenschaften
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/316675121?language=en
• 关键词: FLUOR; Fluorinated; Surfactants; Membrane; Protein

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.

膜蛋白在细胞通讯和运输过程中起着许多重要作用，并代表了大多数药物靶点。然而，我们对膜蛋白结构、动力学和功能的认识和理解进展缓慢，主要是因为它们的疏水性所带来的困难。在体外研究中，这些蛋白质需要一个模拟膜的环境来保持它们的可溶性和活性，这通常是在洗涤剂、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，当溶解在洗涤剂中时，许多膜蛋白会失活，也就是说，它们失去了原有的结构和功能。这促使许多人努力用更温和的替代品取代传统的洗涤剂，其中含氟表面活性剂显得特别有前途。由于碳氟化合物对碳氢化合物的亲和力较弱，而且碳氟化合物的体积较大，因此假定氟化表面活性剂的不稳定性较低，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，多次研究表明，与氢化洗涤剂相比，溶解在含氟表面活性剂中的各种膜蛋白更稳定。然而，不幸的是，中性氟表面活性剂不能溶解脂质双分子层，也不能直接从膜中提取膜蛋白。因此，传统的洗涤剂仍然需要溶解，而氟表面活性剂只有在后期才会发挥作用，那时不稳定的蛋白质已经遭受了不可逆转的损害。我们最近证明，氟化本身并不排除去污性，因为氟化辛烷基麦芽糖衍生物保留温和的洗涤剂样活性。在这个项目中，我们打算利用这一发现来开发、测试和建立含氟洗涤剂，(i)可以合成足够数量和纯度的氟洗涤剂，广泛用于膜蛋白研究；（ii）表现出良好的胶束性质，如小而明确的尺寸；（iii）以快速的、热力学控制的方式分解、跨膜转运和溶解膜；（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洗涤剂；(5)为这些蛋白质提供一个稳定的环境，使其在较长时间内保持其原有的结构和功能。这种含氟洗涤剂将为生理和药理学上有趣的膜蛋白的体外研究开辟新的可能性，这些研究迄今为止一直回避详细审查。这个高度跨学科的项目应该在一个具有合成、物理化学、生物物理、生物化学和结构生物学方面的独特资格的联盟中完成。