Institute of Physical Chemistry, Martin-Luther-University Halle-Wittenberg, 06120, Halle, Germany.
Institute of Physics, Martin-Luther-University Halle-Wittenberg, 06120, Halle, Germany.
Sci Rep. 2018 Feb 1;8(1):2154. doi: 10.1038/s41598-018-20511-0.
Fluorocarbon amphiphiles are anthropogenic substances widely used in diverse applications such as food packaging, clothing or cookware. Due to their widespread use and non-biodegradability, these chemicals are now ubiquitous in the natural world with high propensity to bioaccumulate in biological membranes, wherein they may affect microscopic properties. Here, we test the hypothesis that a typical fluorocarbon amphiphile can affect lipid membranes similarly to cholesterol by investigating the effect of 1H,1H,2H,2H-perfluoro-1-decanol (8:2 FTOH) on 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membranes. Using solid-state nuclear magnetic resonance spectroscopy, differential scanning calorimetry and confocal microscopy, we present a consistent set of independent experimental evidences supporting this hypothesis, namely that upon incorporation of 8:2 FTOH, (i) a condensing effect on the acyl chains occurs in the fluid phase, (ii) coexistence of two membrane phases is observed below melting, and (iii) the melting temperature of DPPC varies no more than approximately ±1 °C up to a concentration of 40 mol% of 8:2 FTOH. The condensing effect is quantified by means of advanced dipolar recoupling solid-state NMR experiments and is found to be of approximately half the magnitude of the cholesterol effect at the same concentration.
全氟脂肪醇是一种人为合成的物质，广泛应用于食品包装、衣物或炊具等领域。由于其广泛的应用和不可生物降解性，这些化学物质现在在自然界中无处不在，具有很强的生物积累倾向，会在生物膜中积聚，并可能影响微观性质。在这里，我们通过研究 1H,1H,2H,2H-全氟-1-癸醇（8:2 FTOH）对 1,2-二月桂酰基-sn-甘油-3-磷酸胆碱（DPPC）膜的影响，验证了一种典型的全氟脂肪醇可以通过类似胆固醇的方式影响脂质膜的假设。利用固态核磁共振波谱、差示扫描量热法和共聚焦显微镜，我们提出了一组一致的独立实验证据来支持这一假设，即：（i）当 8:2 FTOH 掺入时，在流体相中酰基链发生冷凝效应；（ii）在低于熔点时观察到两种膜相共存；（iii）在浓度高达 40mol%的 8:2 FTOH 时，DPPC 的熔点变化不超过约±1°C。通过先进的偶极重聚固态 NMR 实验定量了冷凝效应，发现其在相同浓度下的效应约为胆固醇的一半。
