Department of Chemistry, Guru Nanak Dev University, Amritsar 143005, India.
Department of Physics, School of Natural Sciences, Shiv Nadar Institute of Eminence, NH91, Tehsil Dadri, G. B. Nagar, Greater Noida 201314, Uttar Pradesh, India.
J Phys Chem B. 2024 Jun 6;128(22):5407-5418. doi: 10.1021/acs.jpcb.4c01531. Epub 2024 May 25.
In this work, we explored how the amount of cholesterol in the lipid membrane composed of phosphatidylcholine (POPC) or phosphatidylglycerol (POPG) affects the interaction with 1-dodecyl-3-methylimidazolium bromide ([CMIM]Br) ionic liquids using various biophysical techniques. On interacting with the membrane, [CMIM]Br leads to enhanced membrane permeability and induces membrane fusion, leading to an increase in vesicle size. The H-based solid-state NMR investigations of cholesterol-containing lipid membranes reveal that [CMIM]Br decreases the lipid chain order parameters and counteracts the lipid condensation effect of cholesterol to some extent. Therefore, as the amount of cholesterol in the membrane increases, the membrane effect of [CMIM]Br decreases. The effect of [CMIM]Br on the membrane properties is more pronounced for POPC compared to that of POPG membranes. This suggests a dependence of these effects on the electrostatic interactions, indicating that the influence of [CMIM]Br varies based on the lipid composition. The findings suggest that the presence of cholesterol can modulate the effect of [CMIM]Br on membrane properties, with variations observed between POPC and POPG membranes, highlighting the importance of lipid composition. In short, this study provides insights into the intricate interplay between cholesterol, the lipid membrane, and the ionic liquid [CMIM]Br.
在这项工作中，我们使用各种生物物理技术探索了由磷脂酰胆碱（POPC）或磷脂酰甘油（POPG）组成的脂质膜中的胆固醇含量如何影响与 1-十二烷基-3-甲基咪唑溴化物([CMIM]Br)离子液体的相互作用。[CMIM]Br 与膜相互作用会导致膜通透性增强，并诱导膜融合，从而导致囊泡尺寸增加。含胆固醇脂质膜的 H 基固态 NMR 研究表明，[CMIM]Br 降低了脂质链有序参数，并在一定程度上抵消了胆固醇的脂质凝聚效应。因此，随着膜中胆固醇含量的增加，[CMIM]Br 的膜效应降低。与 POPG 膜相比，[CMIM]Br 对 POPC 膜性质的影响更为明显。这表明这些效应取决于静电相互作用，表明[CMIM]Br 的影响因脂质组成而异。研究结果表明，胆固醇的存在可以调节[CMIM]Br 对膜性质的影响，POPC 和 POPG 膜之间存在差异，突出了脂质组成的重要性。简而言之，本研究深入了解了胆固醇、脂质膜和离子液体[CMIM]Br 之间复杂的相互作用。
