The organization of melatonin in lipid membranes
The organization of melatonin in lipid membranes
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DOI：
10.1016/j.bbamem.2015.01.006
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发表时间：
2015-04-01
影响因子：
3.4
通讯作者：
Rheinstaedter, Maikel C.
中科院分区：
文献类型：
--
作者：
Dies, Hannah;Cheung, Bonnie;Rheinstaedter, Maikel C.
褪黑激素是一种激素，已被证明对多种与胆固醇失调相关的疾病具有保护作用，包括心血管疾病、阿尔茨海默病和某些类型的癌症。我们研究了褪黑激素浓度范围为 0.5 mol% 至 30 mol% 时褪黑激素与由二肉豆蔻酰磷脂酰胆碱 (DMPC) 制成的模型膜的相互作用。通过二维 X 射线衍射测量，我们发现褪黑激素会引起脂质膜的重新排序，这在很大程度上取决于褪黑激素的浓度。在低褪黑激素浓度下，我们观察到膜中存在富含褪黑激素的斑块，这些斑块明显比脂质双层薄。发现褪黑激素分子与这些斑块中的脂质尾部平行排列。在 30 mol% 的高褪黑激素浓度下，我们观察到一种高度有序的褪黑激素结构，该结构在整个膜上是均匀的，其中褪黑激素分子与双层平行排列，并且一个褪黑激素分子与 2 个脂质分子结合。了解褪黑激素在膜中的组织和相互作用，以及它们如何依赖于浓度，可能有助于了解其抗淀粉样蛋白生成、抗氧化和光保护特性，并有助于开发这些特性的结构基础。 (C) 2015 Elsevier B.V. 保留所有权利。
Melatonin is a hormone that has been shown to have protective effects in several diseases that are associated with cholesterol dysregulation, including cardiovascular disease, Alzheimer's disease, and certain types of cancers. We studied the interaction of melatonin with model membranes made of dimyristoylphosphatidylcholine (DMPC) at melatonin concentrations ranging from 0.5 mol% to 30 mol%. From 2-dimensional X-ray diffraction measurements, we find that melatonin induces a re-ordering of the lipid membrane that is strongly dependent on the melatonin concentration. At low melatonin concentrations, we observe the presence of melatonin-enriched patches in the membrane, which are significantly thinner than the lipid bilayer. The melatonin molecules were found to align parallel to the lipid tails in these patches. At high melatonin concentrations of 30 mol%, we observe a highly ordered melatonin structure that is uniform throughout the membrane, where the melatonin molecules align parallel to the bilayers and one melatonin molecule associates with 2 lipid molecules. Understanding the organization and interactions of melatonin in membranes, and how these are dependent on the concentration, may shed light into its anti-amyloidogenic, antioxidative and photoprotective properties and help develop a structural basis for these properties. (C) 2015 Elsevier B.V. All rights reserved.