N-Acyl Chain in Ceramide and Sphingomyelin Determines Their Mixing Behavior, Phase State, and Surface Topography in Langmuir Films
N-Acyl Chain in Ceramide and Sphingomyelin Determines Their Mixing Behavior, Phase State, and Surface Topography in Langmuir Films
复制标题
DOI：
10.1021/jp501686q
复制
发表时间：
2014-07-10
影响因子：
3.3
通讯作者：
Maggio, Bruno
中科院分区：
文献类型：
--
作者：
Dupuy, Fernando G.;Maggio, Bruno
鞘脂是由长链胺二醇碱（通常为鞘氨醇）和N-连接脂肪酰基链组成的膜脂，其质量取决于膜类型。长度和不饱和度的N-酰基链上的不同鞘脂的混合行为的影响几乎没有被研究，在这项工作中，这个问题是解决采用朗缪尔单分子膜在空气-水界面，以评估不同种类的鞘磷脂和神经酰胺的二元混合物的表面混合。的平均分子面积，垂直偶极矩，域偏析，和表面形貌，以及膜的弹性和光学厚度的单层组合物的依赖关系进行了研究。结果表明，鞘磷脂和神经酰胺之间的组合物依赖的有利的相互作用发生作为互补的横向包装和增加的酰基链排序的结果;相状态的组件出现作为一个主要因素，即使在脂质有相当大的烃链长度不匹配的情况下，确定鞘磷脂和神经酰胺之间的兼容性。
Sphingolipids are membrane lipids composed by a long chain aminediol base, usually sphingosine, with a N-linked fatty acyl chain whose quality depends on the membrane type. The effect of length and unsaturation of the N-acyl chain on the mixing behavior of different sphingolipids has scarcely been studied, and in this work this issue is addressed employing Langmuir monolayers at the air-water interface, in order to assess the surface mixing in binary mixtures of different species of sphingomyelins and ceramides. The dependence on the monolayer composition of the mean molecular area, perpendicular dipole moment, domain segregation, and surface topography, as well as the film elasticity and optical thickness were studied. The results indicate that composition-dependent favorable interactions among sphingomyelin and ceramide occur as a consequence of complementary lateral packing and increased acyl chain ordering; the phase state of the components appears as a major factor determining miscibility among sphingomyelins and ceramides even in cases where the lipids have a considerable hydrocarbon chain length mismatch.