Karlovská Janka, Lohner Karl, Degovics Gábor, Lacko Ivan, Devínsky Ferdinand, Balgavý Pavol
Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University, Bratislava SK-832 32, Slovak Republic.
Chem Phys Lipids. 2004 Apr;129(1):31-41. doi: 10.1016/j.chemphyslip.2003.11.003.
Effects of non-ionic surfactants N-alkyl-N,N-dimethylamine-N-oxides (C(n)NO, n is the number of alkyl carbons) on the structure of egg yolk phosphatidylcholine (EYPC) bilayers in the lamellar fluid phase was studied by small-angle X-ray diffraction as a function of H(2)O:EYPC and C(n)NO:EYPC molar ratios. The bilayer thickness d(L) and the lipid surface area at the bilayer-aqueous interface S(L) were calculated from the repeat period, d of the lamellar phase, based on the model that water and EYPC + CnNO molecules form separated layers and that their molecular volumes are additive. In the studied range of m=CnNO:EYPC molar ratios up to 1:1, d(L) and S(L) change linearly. The slopes Delta L = delta dL/ delta m and Delta S= delta S L / delta m are equal to -0.876 +/- 0.027 nm and 0.347 +/- 0.006 nm2 for C(6)NO, -1.025+/-0.060 nm and 0.433+/-0.025 nm(2) for C(8)NO, -0.836+/-0.046 nm and 0.405+/-0.018 nm(2) for C(10)NO, -0.604+/-0.015 nm and 0.375+/-0.007 nm(2) for C(12)NO, -0.279+/-0.031 nm and 0.318+/-0.005 nm(2) for C(14)NO, -0.0865+/-0.070 nm and 0.2963 +/-0.014 nm(2) for C(16)NO, and -0.040+/-0.022 nm and 0.297+/- 0.002 nm(2) for C(18)NO, respectively, at full bilayer hydration. The peak-peak distance in the bilayer electron density profile, which relates to the P-P distance d(PP), obtained from the first four diffraction peaks by the Fourier transform also depends linearly on m, and the slope Delta PP = delta dPP/delta m is -0.528+/-0.065 nm for C(6)NO, -0.680+/-0.018 nm for C(8)NO, -0.573+/-0.021 nm for C(10)NO, -0.369+/-0.075 nm for C(12)NO, -0.190+/-0.015 for C(14)NO, -0.088+/-0.016 nm for C(16)NO and -0.094+/-0.016 nm for C(18)NO. The effects of C(n)NO on Delta(L), Delta(S) and Delta(PP) are the results of C(n)NO insertion into EYPC bilayers and depend on the hydrophobic mismatch between C(n)NO and EYPC hydrocarbon chains and on the lateral interactions of C(n)NO and EYPC in the bilayer.
通过小角X射线衍射研究了非离子表面活性剂N-烷基-N，N-二甲基胺-N-氧化物（C(n)NO，n为烷基碳原子数）对层状流体相中蛋黄磷脂酰胆碱（EYPC）双层结构的影响，该影响是水与EYPC以及C(n)NO与EYPC摩尔比的函数。基于水和EYPC + CnNO分子形成分离层且它们的分子体积具有加和性的模型，从层状相的重复周期d计算双层厚度d(L)和双层-水界面处的脂质表面积S(L)。在所研究的m = CnNO:EYPC摩尔比高达1:1的范围内，d(L)和S(L)呈线性变化。对于C(6)NO，在完全双层水合时，斜率ΔL = ΔdL/Δm和ΔS = ΔSL /Δm分别等于-0.876±0.027 nm和0.347±0.006 nm²；对于C(8)NO，分别为-1.025±0.060 nm和0.433±0.025 nm²；对于C(10)NO，分别为-0.836±0.046 nm和0.405±0.018 nm²；对于C(12)NO，分别为-0.604±0.015 nm和0.375±0.007 nm²；对于C(14)NO，分别为-0.279±0.031 nm和0.318±0.005 nm²；对于C(16)NO，分别为-0.0865±0.070 nm和0.2963±0.014 nm²；对于C(18)NO分别为-0.040±0.022 nm和0.297±0.002 nm²。通过傅里叶变换从最初四个衍射峰获得的与P-P距离d(PP)相关的双层电子密度分布中的峰-峰距离也线性依赖于m，对于C(6)NO，斜率ΔPP = ΔdPP/Δm为-0.528±0.065 nm；对于C(8)NO为-0.680±0.018 nm；对于C(10)NO为-0.
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