Gómez-Murcia Victoria, Torrecillas Alejandro, de Godos Ana M, Corbalán-García Senena, Gómez-Fernández Juan C
Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia, IMIB-Arrixaca, Campus of International Excellence "Campus Mare Nostrum", Murcia, Spain.
Biochim Biophys Acta. 2016 Jun;1858(6):1071-81. doi: 10.1016/j.bbamem.2016.02.034. Epub 2016 Feb 27.
Idebenone is a synthetic analog of coenzyme Q; both share a quinone moiety but idebenone has a shorter lipophilic tail ending with a hydroxyl group. Differential scanning calorimetry experiments showed that both idebenone and idebenol widened and shifted the phase transition of 1,2-dipalmitoylphosphatidylcholine (DPPC) to a lower temperature and a phase separation with different concentrations of these molecules was observed. Also small angle X-ray diffraction and wide angle X-ray diffraction revealed that both, idebenone and idebenol, induced laterally separated phases in fluid membranes when included in DPPC membranes. Electronic profiles showed that both forms, idebenone and idebenol, reduced the thickness of the fluid membrane. (2)H NMR measurements showed that the order of the membrane decreased at all temperatures in the presence of idebenone or idebenol, the greatest disorder being observed in the segments of the acyl chains close to the lipid-water interface. (1)H NOESY MAS NMR spectra were obtained using 1-palmitoyl-2-oleoyl-phosphatidylcholine membranes and results pointed to a similar location in the membrane for both forms, with the benzoquinone or benzoquinol rings and their terminal hydroxyl group of the hydrophobic chain located near the lipid/water interface of the phospholipid bilayer and the terminal hydroxyl group of the hydrophobic chain of both compounds located at the lipid/water interface. Taken together, all these different locations might explain the different physiological behavior shown by the idebenone/idebenol compared with the ubiquinone-10/ubiquinol-10 pair in which both compounds are differently localized in the membrane.
艾地苯醌是辅酶Q的合成类似物；二者都含有醌部分，但艾地苯醌的亲脂性尾部较短，末端为羟基。差示扫描量热法实验表明，艾地苯醌和艾地苯酚都使1,2 -二棕榈酰磷脂酰胆碱（DPPC）的相变变宽并向低温移动，且观察到这些分子在不同浓度下会发生相分离。此外，小角X射线衍射和广角X射线衍射显示，当艾地苯醌和艾地苯酚包含在DPPC膜中时，二者都会在流体膜中诱导横向分离相。电子轮廓显示，艾地苯醌和艾地苯酚两种形式都会降低流体膜的厚度。（2）H NMR测量表明，在存在艾地苯醌或艾地苯酚的情况下，膜在所有温度下的有序度都会降低，在靠近脂质 - 水界面的酰基链段中观察到最大程度的无序。使用1 - 棕榈酰 - 2 - 油酰 - 磷脂酰胆碱膜获得了（1）H NOESY MAS NMR光谱，结果表明两种形式在膜中的位置相似，苯醌或苯醌醇环及其疏水链的末端羟基位于磷脂双层的脂质/水界面附近，两种化合物疏水链的末端羟基位于脂质/水界面。综上所述，所有这些不同的位置可能解释了与泛醌 - 10/泛醇 - 10对相比，艾地苯醌/艾地苯酚所表现出的不同生理行为，在泛醌 - 10/泛醇 - 10对中，两种化合物在膜中的定位不同。
