Formation of Gel-like Nanodomains in Cholesterol-Containing Sphingomyelin or Phosphatidylcholine Binary Membrane As Examined by Fluorescence Lifetimes and (2)H NMR Spectra.
Formation of Gel-like Nanodomains in Cholesterol-Containing Sphingomyelin or Phosphatidylcholine Binary Membrane As Examined by Fluorescence Lifetimes and (2)H NMR Spectra.
复制标题
通过荧光寿命和 (2)H NMR 光谱检查含胆固醇的鞘磷脂或磷脂酰胆碱二元膜中凝胶状纳米结构域的形成。
作者：
Tomokazu Yasuda;N. Matsumori;H. Tsuchikawa;Max Lönnfors;T. Nyholm;J. Slotte;M. Murata
在这项研究中，我们测量了反式parinaric酸（tPA）的时间分辨荧光，二苯基己三烯（DPH）的稳态荧光各向异性，和（2）10，10-d2-硬脂酰脂质在硬脂酰鞘磷脂与胆固醇（SSM/Chol）和1-棕榈酰-2-硬脂酰-sn-甘油-3-磷酸胆碱与Chol（PSPC/Chol）二元膜的H NMR。结果表明，从荧光实验中获得的膜顺序显示出类似的温度依赖性的（2）H NMR数据。更重要的是，时间分辨荧光数据暗示存在至少两种类型的结构域，胆固醇贫乏的凝胶样结构域（CPGLD）和胆固醇富集的液体有序（Lo）结构域。对于SSM-Chol和PSPC-Chol膜，这些域出现在纳米至微米的时间尺度上。凝胶状结构域的相对大小也由温度依赖的寿命测量和（2）H NMR光谱变化估计。结果表明，SM-Chol膜中的凝胶状结构域的尺寸很小，可能在纳米尺度上，并且比PSPC-Chol双层膜中的小，这可能是SM-Chol膜具有更高热稳定性的原因。本研究表明，凝胶状纳米结构域发生在SM-Chol二元膜，即使与胆固醇含量超过33摩尔%，这已被认为是专门由Lo相，这意味着不仅Lo域，但也凝胶状纳米结构域是重要的脂质有序相的形成SM-Chol和PC-胆固醇膜。
In this study, we measured the time-resolved fluorescence of trans-parinaric acid (tPA), steady-state fluorescence anisotropy of diphenylhexatriene (DPH), and (2)H NMR of 10,10-d2-stearoyl lipids in stearoyl sphingomyelin with cholesterol (SSM/Chol) and l-palmitoyl-2-stearoyl-sn-glycero-3-phosphocholine with Chol (PSPC/Chol) binary membranes. The results suggest that the membrane order obtained from the fluorescence experiments shows a similar temperature dependency as those of the (2)H NMR data. More importantly, the time-resolved fluorescence data implied the presence of at least two types of domains, cholesterol-poor gel-like domains (CPGLD) and cholesterol-enriched liquid-ordered (Lo) domains. These domains appear on a nano-to-micro second time scale for both SSM-Chol and PSPC-Chol membranes. The relative size of the gel-like domain was also estimated from the temperature-dependent lifetime measurements and (2)H NMR spectral changes. The results imply that the size of the gel-like domains is very small, probably on the nanometer scale, and smaller in SSM-Chol membrane than those in PSPC-Chol bilayers, which could account for the higher thermal stability of SM-Chol membranes. The present study demonstrates that gel-like nanodomains occur in SM-Chol binary membrane even with Chol content of over 33 mol %, which has been thought to consist exclusively of Lo phase, implying that not only Lo domains but also gel-like nanodomains are important for formation of lipid-ordered phase in SM-Chol and PC-Chol membranes.
石蜡酸的四种异构体的合成。
DOI：
10.1016/j.chemphyslip.2004.06.001
发表时间：
2004
期刊：
Chemistry and physics of lipids.
影响因子：
--
作者：
Kuklev,DmitryV;Smith,WilliamL
通讯作者：
Smith,WilliamL
影响因子：
2.9
作者：
Xu, XL;London, E
通讯作者：
London, E
影响因子：
3.4
作者：
Veatch, SL;Keller, SL
通讯作者：
Keller, SL