NMR-based conformational analysis of sphingomyelin in bicelles
NMR-based conformational analysis of sphingomyelin in bicelles
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DOI：
10.1016/j.bmc.2011.11.001
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发表时间：
2012-01-01
影响因子：
3.5
通讯作者：
Murata, Michio
中科院分区：
文献类型：
--
作者：
Yamaguchi, Toshiyuki;Suzuki, Takashi;Murata, Michio
鞘磷脂（SM）是哺乳动物细胞膜中常见的鞘脂，并且已知其实质上参与细胞事件，例如脂筏的形成。尽管它的生物学意义，SM在膜环境中的构象仍然不清楚，因为非结晶性和各向异性的脂质双层环境阻碍了X射线晶体学和NMR测量的应用。在这项研究中，为了阐明SM在膜中的构象，我们利用双胞作为脂质双层膜的替代品。首先，我们证明了通过P-31 NMR，H-2 NMR，和动态光散射实验，SM形成取向和各向同性bicelles通过改变SM/二己酰磷脂酰胆碱的比例。然后，我们确定了SM在各向同性bicelles的耦合常数和NOE相关的基础上在H-1 NMR的构象，发现SM的C2-C6和酰胺基团在bicelles采取相对刚性构象。(C)2011爱思唯尔有限公司保留所有权利。
Sphingomyelin (SM) is a common sphingolipid in mammalian membranes and is known to be substantially involved in cellular events such as the formation of lipid rafts. Despite its biological significance, conformation of SM in a membrane environment remains unclear because the noncrystalline property and anisotropic environment of lipid bilayers hampers the application of X-ray crystallography and NMR measurements. In this study, to elucidate the conformation of SM in membranes, we utilized bicelles as a substitute for a lipid bilayer membrane. First, we demonstrated through P-31 NMR, H-2 NMR, and dynamic light scattering experiments that SM forms both oriented and isotropic bicelles by changing the ratio of SM/dihexanoyl phosphatidylcholine. Then, we determined the conformation of SM in isotropic bicelles on the basis of coupling constants and NOE correlations in H-1 NMR and found that the C2-C6 and amide groups of SM take a relatively rigid conformation in bicelles. (C) 2011 Elsevier Ltd. All rights reserved.