Uhríková Daniela, Hanulová Mária, Funari Sérgio S, Lacko Ivan, Devínsky Ferdinand, Balgavý Pavol
Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32 Bratislava, Slovakia.
Biophys Chem. 2004 Nov 1;111(3):197-204. doi: 10.1016/j.bpc.2004.05.012.
The structure of aggregates formed by interaction of DNA with unilamellar dilauroylphosphatidylcholine (DLPC) vesicles (DNA:DLPC=1:1 base/mol) in the presence of gemini surfactant butane-1,4-diyl-bis(dodecyldimethylammonium bromide) (C12GS) was investigated using synchrotron small angle X-ray diffraction. In the concentration range C12GS+:DLPC< or =1 mol/mol, a condensed lamellar Lalphac phase was found with a repeat period of lipid bilayer stacking in the range d approximately 5.70-6.53 nm and the DNA interhelical distance d(DNA) approximately 3.52-3.99 nm, depending on the concentration of C12GS. At molar ratio C12GS+:DLPC> or =0.35:1, the diffractograms have shown the presence of a second lamellar phase with the repeat period d approximately 5.31 nm which slightly decreases with increasing concentration of C12GS+. The increasing fraction of this phase in the aggregates with increasing concentration of C12GS supports the association of this phase with microscopic domains enriched by surfactant molecules. The temperature behaviour of aggregates was investigated in the range 25-60 degrees C and the transversal thermal expansivities of the observed phases were determined.
利用同步加速器小角X射线衍射研究了在双子表面活性剂丁烷-1,4-二基-双（十二烷基二甲基溴化铵）（C12GS）存在下，DNA与单层二月桂酰磷脂酰胆碱（DLPC）囊泡（DNA:DLPC = 1:1碱基/摩尔）相互作用形成的聚集体结构。在C12GS+:DLPC≤1摩尔/摩尔的浓度范围内，发现了一种凝聚的层状Lαc相，其脂质双层堆积的重复周期d在约5.70 - 6.53 nm范围内，DNA螺旋间距离d(DNA)约为3.52 - 3.99 nm，这取决于C12GS的浓度。在摩尔比C12GS+:DLPC≥0.35:1时，衍射图显示存在第二个层状相，其重复周期d约为5.31 nm，随C12GS+浓度增加略有减小。随着C12GS浓度增加聚集体中该相的比例增加，这支持了该相与富含表面活性剂分子的微观区域的关联。研究了聚集体在25 - 60℃范围内的温度行为，并测定了观察到的相的横向热膨胀系数。
