Rapid flip-flop in polyunsaturated (docosahexaenoate) phospholipid membranes
Rapid flip-flop in polyunsaturated (docosahexaenoate) phospholipid membranes
复制标题
DOI：
10.1016/s0003-9861(03)00159-0
复制
发表时间：
2003-06-01
影响因子：
3.9
通讯作者：
Stillwell, W
中科院分区：
文献类型：
--
作者：
Armstrong, VT;Brzustowicz, MR;Stillwell, W
用连二亚硫酸钠猝灭7-硝基苯-2-氧杂-1，3-二氮唑-4-基磷脂酰乙醇胺（NBD-PE）荧光的方法，研究了NBD-PE在不同酰基链的磷脂酰胆碱（PC）膜中的跨双层运动。特别令人感兴趣的是二十二碳六烯酸（DHA），这是膜中常见的最长和最不饱和的酰基链。这种分子代表了一个被称为omega-3的重要脂肪酸家族的极端例子，并已被清楚地证明可以改变膜结构和功能。尚未报道的一个重要特性是DHA对膜磷脂翻转的影响。该研究表明，随着构成膜的脂肪酰基链中双键数量的增加，NBD-PE探针的翻转速率也增加。这种增加在DHA的存在下特别明显。半衰期t（1/2）分别为0.29和0.086 h，描述了1-硬脂酰-2-二十二碳六烯酰磷脂酰胆碱和1，2-二二十二碳六烯酰磷脂酰胆碱中的过程，而在1-硬脂酰-2-油酰磷脂酰胆碱中，t（1/2）= 11.5 h。我们的研究结果还表明，随着不饱和度的增加，连二亚硫酸盐的渗透性增强。我们的结论是，PC膜含有DHA支持更快的触发器和渗透率比其他不饱和PC的测量。(C)2003 Elsevier Science（美国）。All rights reserved.
The transbilayer movement (flip-flop) of 7-nitrobenz-2-oxa-1,3-diazol-4-yl phosphatidylethanolamine (NBD-PE) in phosphatidylcholine (PC) membranes containing various acyl chains was measured by dithionite quenching of NBD fluorescence. Of specific interest was docosahexaenoic acid (DHA), the longest and most unsaturated acyl chain commonly found in membranes. This molecule represents the extreme example of a family of important fatty acids known as omega-3s and has been clearly demonstrated to alter membrane structure and function. One important property that has yet to be reported is the effect of DHA on membrane phospholipid flip-flop. This study demonstrates that as the number of double bonds in the fatty acyl chains comprising the membrane increases, so does the rate of flip-flop of the NBD-PE probe. The increase is particularly marked in the presence of DHA. Half-lives t(1/2) of 0.29 and 0.086h describe the process in 1-stearoyl-2-docosahexaenoylphosphatidylcholine and 1,2-didocosahexaenoylphosphatidylcholine, respectively, whereas in 1-stearoyl-2-oleoylphosphatidylcholine t(1/2) = 11.5 h. Enhanced permeability to dithionite with increasing unsaturation was also indicated by our results. We conclude that PC membranes containing DHA support faster flip-flop and permeability rates than those measured for other less-unsaturated PCs. (C) 2003 Elsevier Science (USA). All rights reserved.