Kucerka Norbert, Gallová Jana, Uhríková Daniela, Balgavý Pavol, Bulacu Monica, Marrink Siewert-Jan, Katsaras John
Canadian Neutron Beam Centre, National Research Council, Chalk River, Ontario, Canada.
Biophys J. 2009 Oct 7;97(7):1926-32. doi: 10.1016/j.bpj.2009.06.050.
We have studied the structural properties of monounsaturated diacylphosphatidylcholine lipid bilayers (i.e., diCn:1PC, where n = 14, 16, 18, 20, 22, and 24 is the number of acyl chain carbons). High-resolution x-ray scattering data were analyzed in conjunction with contrast-varied neutron scattering data using a technique we recently developed. Analyses of the data show that the manner by which bilayer thickness increases with increasing n in monounsaturated diacylphosphatidylcholines is dependent on the double bond's position. For commonly available monounsaturated diacylphosphatidylcholines, this results in the nonlinear behavior of both bilayer thickness and lipid area, whereas for diC18:1PC bilayers, lipid area assumes a maximum value. It is worthwhile to note that compared to previous data, our results indicate that lipid areas are smaller by approximately 10%. This observation highlights the need to revisit lipid areas, as they are often used in comparisons with molecular dynamics simulations. Moreover, simulators are encouraged to compare their results not only to x-ray scattering data, but to neutron data as well.
我们研究了单不饱和二酰基磷脂酰胆碱脂质双层（即二Cn:1PC，其中n = 14、16、18、20、22和24为酰基链碳原子数）的结构特性。利用我们最近开发的一项技术，将高分辨率x射线散射数据与对比变化的中子散射数据结合起来进行分析。数据分析表明，在单不饱和二酰基磷脂酰胆碱中，双层厚度随n增加而增加的方式取决于双键的位置。对于常见的单不饱和二酰基磷脂酰胆碱，这导致双层厚度和脂质面积均呈现非线性行为，而对于二C18:1PC双层，脂质面积呈现最大值。值得注意的是，与先前的数据相比，我们的结果表明脂质面积大约小10%。这一观察结果凸显了重新审视脂质面积的必要性，因为脂质面积经常用于与分子动力学模拟进行比较。此外，鼓励模拟人员不仅将他们的结果与x射线散射数据进行比较，还要与中子数据进行比较。
