Plasmon-waveguide resonance and impedance spectroscopy studies of the interaction between penetratin and supported lipid bilayer membranes
Plasmon-waveguide resonance and impedance spectroscopy studies of the interaction between penetratin and supported lipid bilayer membranes
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DOI：
10.1016/s0006-3495(03)74987-x
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发表时间：
2003-03-01
影响因子：
3.4
通讯作者：
Tollin, G
中科院分区：
文献类型：
--
作者：
Salamon, Z;Lindblom, G;Tollin, G
通过同时测量脂质-肽混合物的等离子体波导共振（PWR）光谱和阻抗光谱，研究了细胞穿透肽、穿透素和由蛋磷脂酰胆碱（PC）或蛋磷脂酰磷脂酰甘油（75% / 25mol %）混合物组成的固体支撑脂质双层膜之间的相互作用。当将渗透素掺入蛋PC +棕榈酰油基磷脂酰甘油双分子层时，PWR测量结果显示，在0 ~ 2 ma肽浓度范围内，平均折射率和折射率各向异性呈双曲线增加，膜厚度没有变化。在卵磷脂双分子层中，观察到双相依赖性，平均折射率和各向异性降低，在0和5个muM肽之间没有厚度变化，在5和15个muM肽之间膜厚度增加，折射率参数没有进一步变化。对于两种膜，阻抗谱测量表明，电阻不会因肽的掺入而改变，而膜电容的下降与在PWR实验中观察到的浓度依赖性相同，尽管对于PC膜，在较高的浓度范围内没有观察到进一步的电性能变化。描述了这些结果的结构解释，其中肽在双分子层的头基区域内静电结合，并影响头基构象，结合水的数量和脂质堆积密度，而不干扰双分子层的碳氢化合物核心。
The interaction between the cell-penetrating peptide, penetratin, and solid-supported lipid bilayer membranes consisting of either egg phosphatidylcholine (PC) or a 75/25 mol% mixture of egg PC and palmitoyloleylphosphatidylglycerol has been studied by simultaneously measuring plasmon-waveguide resonance (PWR) spectra and impedance spectra of lipid-peptide mixtures. When penetratin was incorporated into an egg PC + palmitoyloleylphosphatidylglycerol bilayer, PWR measurements showed a hyperbolic increase in the average refractive index and the refractive index anisotropy, with no change in membrane thickness, over a concentration range between 0 and 2 muM peptide. In the case of an egg PC bilayer, a biphasic dependence was observed, with a decrease in average refractive index and anisotropy and no thickness change occurring between 0 and 5 muM peptide, and an increase in membrane thickness occurring between 5 and 15 muM peptide with no further change in the refractive index parameters. For both membranes, the impedance spectroscopy measurements demonstrated that the electrical resistance was not altered by peptide incorporation, whereas a decrease in membrane capacitance occurred with the same concentration dependence as observed in the PWR experiments, although for the PC membrane no further changes in electrical properties were observed in the higher concentration range. A structural interpretation of these results is described, in which the peptide binds electrostatically within the headgroup region of the bilayer and influences the headgroup conformation, amount of bound water, and the lipid-packing density, without perturbing the hydrocarbon core of the bilayer.