2 TYPES OF HYDROCARBON CHAIN INTERDIGITATION IN SPHINGOMYELIN BILAYERS
2 TYPES OF HYDROCARBON CHAIN INTERDIGITATION IN SPHINGOMYELIN BILAYERS
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DOI：
10.1021/bi00343a036
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发表时间：
1985-01-01
期刊：
影响因子：
2.9
通讯作者：
HUANG, C
中科院分区：
文献类型：
--
作者：
LEVIN, IW;THOMPSON, TE;HUANG, C
合成的DL-erythro-N-lignoceroylsphingosylphosphocholine[C(24)：Spm]是两个高度不对称的碳氢链长的神经鞘磷脂的外消旋混合物，其水分散体的振动拉曼光谱实验是温度的函数。C-H伸缩模区振动跃迁的拉曼光谱峰高比表明，C(24)：SPM-H2O体系经历了以48.5和54.5度为中心的两个热相变。C.完全水合的C(24)：SPM的振动数据与高度不对称的磷脂酰胆碱分散体的振动数据进行了比较。拉曼光谱数据与较低温度转变可归因于混合交指凝胶态(Gel II)向部分交错凝胶态(Gel I)转变以及较高温度转变对应于凝胶I(Gel I.fwdarw)的合理模型一致。液晶相变。在低于48.5度的温度下观察到混合交错的凝胶状态(Gel II)。C意味着生物膜可能具有脂质结构域，其中一些脂质碳氢链完全贯穿脂质双层的整个碳氢化合物宽度。
Vibrational Raman spectroscopic experiments have been performed as a function of temperature on aqueous dispersions of synthetic DL-erythro-N-lignoceroylsphingosylphosphocholine [C(24):SPM], a racemic mixture of two highly asymmetric hydrocarbon chain length sphingomyelins. Raman spectral peak-height intensity ratios of vibrational transitions in the C-H stretching-mode region show that the C(24):SPM-H2O system undergoes two thermal phase transitions centered at 48.5 and 54.5.degree. C. Vibrational data for fully hydrated C(24):SPM are compared to those of highly asymmetric phosphatidylcholine dispersions. The Raman data are consistent with the plausible model that the lower temperature transition can be ascribed to the conversion of a mixed interdigitated gel state (gel II) to a partially interdigitated gel state (gel I) and that the higher temperature transition corresponds to a gel I .fwdarw. liquid-crystalline phase transition. The observation of a mixed interdigited gel state (gel II) at temperatures below 48.5.degree. C implies that biological membranes may have lipid domains in which some of the lipid hydrocarbon chains penetrate completely across the entire hydrocarbon width of the lipid bilayer.