Arsov Zoran, Quaroni Luca
TASC INFM-CNR, Strada Statale 14 km 163.5, 34012 Basovizza, Trieste, Italy.
Chem Phys Lipids. 2007 Nov;150(1):35-48. doi: 10.1016/j.chemphyslip.2007.06.215. Epub 2007 Jun 23.
By using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and curve fitting we have examined temperature dependence and composition dependence of the shape of the carbonyl band in phosphatidylcholine/cholesterol model membranes. Membranes were hydrated either in excess water or in excess deuterated water. The studied binary mixtures exhibit different lipid phases at appropriate temperature and amount of cholesterol, among them also the so-called liquid-ordered phase. The results confirm that cholesterol has a significant indirect influence on the carbonyl band through conformational and hydration effects. This influence was interpreted in view of the known temperature composition phase diagrams for inspected binary mixtures. In addition, direct interaction was observed, which could point to the presence of hydrogen bond between cholesterol and carbonyl group. This direct interaction, though weak, might play at least a partial role in the stabilization of cholesterol-rich lipid domains in model and biological membranes.
通过使用衰减全反射傅里叶变换红外（ATR-FTIR）光谱法和曲线拟合，我们研究了磷脂酰胆碱/胆固醇模型膜中羰基带形状的温度依赖性和组成依赖性。膜在过量水或过量重水中水合。所研究的二元混合物在适当的温度和胆固醇含量下呈现不同的脂质相，其中还包括所谓的液相有序相。结果证实，胆固醇通过构象和水合作用对羰基带具有显著的间接影响。根据所检测二元混合物的已知温度组成相图对这种影响进行了解释。此外，还观察到了直接相互作用，这可能表明胆固醇与羰基之间存在氢键。这种直接相互作用虽然较弱，但可能至少在模型膜和生物膜中富含胆固醇的脂质结构域的稳定中发挥部分作用。
