Massey J B
Department of Medicine, Baylor College of Medicine, 6565 Fannin Street, M.S.A.-601, Houston, TX 77030, USA.
Chem Phys Lipids. 2001 Feb;109(2):157-74. doi: 10.1016/s0009-3084(00)00216-4.
alpha-Tocopherol and alpha-tocopheryl succinate are biologically active lipids. The activity of these lipids may be related to how they affect membrane physical-chemical properties. Utilizing fluorescence methods, we have investigated the effect of alpha-tocopherol, alpha-tocopheryl succinate, and alpha-tocopheryl acetate on the properties of model membranes consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine. In liquid-crystalline phase phospholipid bilayers, alpha-tocopherol decreased acyl chain mobility and decreased the interfacial polarity, but had no effect on the interfacial surface charge. In contrast, alpha-tocopheryl succinate had little effect on acyl chain motion or interfacial hydration, but increased the interfacial surface charge. alpha-Tocopheryl acetate had very little effect on any of the measurements of these bilayer properties. In a gel phase bilayer, alpha-tocopherol decreased acyl chain order, whereas alpha-tocopheryl succinate and alpha-tocopheryl acetate did not. Each alpha-tocopheryl derivative had a different effect on interfacial polarity, however, only alpha-tocopheryl succinate increased the interfacial surface charge. The acylation of alpha-tocopherol abolishes its antioxidant activity and generates molecules with different membrane physical properties. The non-polar acetate group of alpha-tocopheryl acetate locates this compound in a region of the bilayer where it has little effect on bilayer interfacial properties. The free carboxyl group of alpha-tocopheryl succinate is located in the interfacial region of the bilayer where it increases the membrane surface charge.
α-生育酚和α-生育酚琥珀酸酯是具有生物活性的脂质。这些脂质的活性可能与它们对膜物理化学性质的影响方式有关。利用荧光方法，我们研究了α-生育酚、α-生育酚琥珀酸酯和α-生育酚乙酸酯对由1-棕榈酰-2-油酰-sn-甘油-3-磷酸胆碱和1,2-二棕榈酰-sn-甘油-3-磷酸胆碱组成的模型膜性质的影响。在液晶相磷脂双层中，α-生育酚降低了酰基链的流动性并降低了界面极性，但对界面表面电荷没有影响。相比之下，α-生育酚琥珀酸酯对酰基链运动或界面水合作用影响很小，但增加了界面表面电荷。α-生育酚乙酸酯对这些双层性质的任何测量结果影响都非常小。在凝胶相双层中，α-生育酚降低了酰基链的有序性，而α-生育酚琥珀酸酯和α-生育酚乙酸酯则没有。然而，每种α-生育酚衍生物对界面极性都有不同的影响，只有α-生育酚琥珀酸酯增加了界面表面电荷。α-生育酚的酰化消除了其抗氧化活性，并产生了具有不同膜物理性质的分子。α-生育酚乙酸酯的非极性乙酸基团使该化合物定位在双层的一个区域，在该区域它对双层界面性质影响很小。α-生育酚琥珀酸酯的游离羧基位于双层的界面区域，在该区域它增加了膜表面电荷。
