Use of Fourier transforms in the analysis of fluorescence data. 3. Fluorescence of pyrene-labeled phosphatidylcholine in lipid bilayer membrane: a three-state model
Use of Fourier transforms in the analysis of fluorescence data. 3. Fluorescence of pyrene-labeled phosphatidylcholine in lipid bilayer membrane: a three-state model
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在荧光数据分析中使用傅立叶变换。
DOI：
10.1021/j100172a073
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
P. Chong
中科院分区：
文献类型：
--
作者：
I. Sugár;J. Zeng;P. Chong
本文提出了一个三态模型来描述芘标记的磷脂在脂膜中的荧光。三态模型是Birks模型的推广（Birks等人，Proc.R. Soc.伦敦，A 1963，275，575-588），其在膜系统的情况下被证明是失败的。与Birks模型相反，三态模型区分了两种类型的激发单体：在最近邻有和没有基态探针分子的激发单体。基态探针分子在激发态单体最近邻的存在可能导致激基缔合物在相应芘环的适当取向上形成。荧光过程的动力学模型由三个耦合的一阶线性微分方程表示，其系数取决于探针浓度。的系数的浓度依赖性的分析形式确定通过伊辛型模型的双组分膜。反应动力学和统计力学的结合应用提供了一个适当的描述芘荧光的情况下，理想和非理想的混合物组成的芘标记的探针和基质脂质分子。通过使用三态模型的显式解，对稳态和相位调制荧光数据的全局分析提供了关于荧光速率参数以及芘标记的脂质分子在膜中的横向分布的静态和动态参数的信息。TV-[10-（1-芘基）癸酰基]磷脂酰胆碱（PyrPC）在1，2-二肉豆蔻酰-La-磷脂酰胆碱（DMPC）多层囊泡中的分布表明：PyrPC分子在脂质基质中倾向于最大程度地分离，在膜中形成规则而不是完全随机的分布; PyrPC的横向扩散系数在30.3 ℃下在液晶相中为23 μ 2 s-1，在10 ℃下在凝胶相中为2.6 μ 2 s-1;芘部分的旋转扩散速率在液晶相中为5.1 × 107 s-1，在凝胶相中为9 × 107 s-1。
In this paper a three-state model has been developedto describe the fluorescence of pyrene-labeled phospholipids inlipid membranes. The three-state model is a generalization of the Birks model (Birks et al. Proc. R. Soc. London, A 1963, 275, 575-588), which proved to fail in the case of membrane systems. In contrast to the Birksmodel, the three-state model makes a distinction between two types of the excited monomers: excited monomers that have and that have no ground-state probe molecules intheir nearest neighbor. The presence of ground-state probe molecules in the nearest neighbor of an excited monomer may resultin excimer formation at proper orientations of the respective pyrene rings. The kinetics of the fluorescence process is represented in the model bythree coupled, first-order, linear differential equations with coefficients depending on the probe concentration. The analytical forms of the concentration dependencies of the coefficients are determined by means of an Ising type model of the two-component membranes. This combined application of reaction kinetics and statistical mechanics provides a proper description of the pyrene fluorescence in the cases of both ideal and nonideal mixtures composed of pyrene-labeled probes and matrix lipid molecules. By using the explicit solutions of the three state model, the global analysis of the steady-state and phase-modulation fluorescence data provides informations on the fluorescence rate parameters and on the static and dynamic parameters of the lateral distributionof the pyrene-labeled lipid molecules in the membrane. The analysis of the fluorescence of TV-[10-(1-pyrenyl) decanoyl] phosphatidylcholine (PyrPC) in multilamellar vesicles of 1, 2-dimyristoyl-La-phosphatidylcholine (DMPC) shows the following: the PyrPC molecules tend to be maximally separated in the lipid matrix forming regular rather than completely random distribution in the membrane; the lateral diffusion coefficient of the PyrPC is 23 µ 2 s" 1 in the liquid crystalline phase at 30.3 C and 2.6 µ 2 s'1 in the gel phase at 10 C; the rotational diffusion rate of the pyrene moiety is 5.1 X 10® s" 1 in the liquid-crystalline phase and 9 X 107 s'1 in the gel phase.