Fluorescence quenching in model membranes: phospholipid acyl chain distributions around small fluorophores.
Fluorescence quenching in model membranes: phospholipid acyl chain distributions around small fluorophores.
复制标题
模型膜中的荧光猝灭：小荧光团周围的磷脂酰基链分布。
DOI：
10.1021/bi00470a018
复制
发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
Feigenson,GW
中科院分区：
文献类型：
--
作者：
Yeager,MD;Feigenson,GW
Mark D. Yeager 1和Gerald W. Feigenson ** Section of Biochemistry，Molecular and Cell Biology，Cornell University，Ithaca，纽约14853接收于1989年8月7日;修订于1989年12月20日摘要：脂质双层中的荧光猝灭是通过一种新的方法来处理的，该方法基于荧光团周围猝灭和非猝灭酰基链的概率分布的计算。酰基晶格位点依赖性（即相邻位点磷脂姐妹链占据的相关性）的影响通过使用酰基链占据的Monte Carlo模拟来建模。发现这种明确的占位相关性的解释比其中磷脂猝灭剂被认为是独立的模型更好地拟合观察到的猝灭行为。这种方法的一个关键方面是评估由纯淬灭脂质组成的双层中的淬灭速率。为了评估这种猝灭率，也提供了一个强有力的测试计算的概率分布，我们合成了脂质与两个酰基链标记的猝灭部分（溴或氮氧化物），以及更常见的单链猝灭剂。本文研究了色氨酸辛酯（TOE）、1，6-二苯基-1，3，5-己三烯（DPH）衍生物三甲基铵-DPH（TMA-DPH）和1-月桂酰-2-（DPH-丙酰）磷脂酰胆碱（DPH-PC）的荧光性质。我们得到了一致的结果与所有的荧光团和淬灭剂表明，多达18个相邻的酰基网站可以有助于淬灭，对应于两个壳的酰基网站上的六方晶格。计算的离散分布的荧光强度转换成荧光寿命和比较高斯和洛伦兹连续寿命分布。本文提出的荧光猝灭理论可用于定量解释多组分膜中荧光团环境的异质性。
Mark D. Yeager1 and Gerald W. Feigenson** Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853 Received August 7, 1989; Revised Manuscript Received December 20, 1989 abstract: Fluorescence quenching in lipid bilayers is treated by a new approach based on calculation of the probability distribution of quenching and nonquenching acyl chains around a fluorophore. The effect of acyl lattice site dependence (ie, correlations of phospholipid sister chain occupancy of neighbor sites) was modeled by use of Monte Carlo simulations of acyl chain occupancy. This explicit accounting of site occupancy correlation was found to fit observed quenching behavior better than did a model wherein phospholipid quenchers are considered to be independent. A key aspect of this approach is to evaluate the rate for quenching in a bilayer composed of pure quenching lipid. In order to evaluate this quenching rate, and also to provide a strong test of the calculated probability distributions, we synthesized lipidswith both acyl chains labeled with a quenching moiety (Br or nitroxide), as well as the more usual single-chain quenchers. The fluorescence of tryptophan octyl ester (TOE), and of the 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) derivatives trimethylammonium-DPH (TMA-DPH) and l-lauroyl-2-(DPH-propionyl) phosphatidylcholine (DPH-PC), was examined. We obtained consistent results with all the fluorophores and quenchers indicating that up to 18 neighboring acyl sites can contribute to quenching, corresponding to twoshells of acyl sites on a hexagonal lattice. Calculated discrete distributions of fluorescence intensities were converted into fluorescence lifetimes and compared with Gaussian and Lorentzian continuous lifetime distributions. Thefluorescence quenching theory presented here may be used to explainquantitatively the heterogeneity of fluorophore environments in multicomponent membranes.