Importance of the phosphocholine linkage on sphingomyelin molecular properties and interactions with cholesterol;: a study with phosphate oxygen modified sphingomyelin-analogues
Importance of the phosphocholine linkage on sphingomyelin molecular properties and interactions with cholesterol;: a study with phosphate oxygen modified sphingomyelin-analogues
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DOI：
10.1016/j.bbamem.2008.03.005
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发表时间：
2008-06-01
影响因子：
3.4
通讯作者：
Slotte, J. Peter
中科院分区：
文献类型：
--
作者：
Bjorkbom, Anders;Yamamoto, Tetsuya;Slotte, J. Peter
我们已经表征了合成修饰的鞘磷脂类似物的分子性质和膜行为，其在连接磷酸胆碱基团与神经酰胺主链的氧上进行了修饰。氧被S-原子（S-PSM）、NH-基团（NH-PSM）或CH 2-基团（CH 2-PSM）取代。二苯基己三烯和Laurdan各向异性实验表明，一个S-键增加和NH-和CH 2-键降低PSM类似物双层膜的稳定性相比，PSM。当使用Laurdan探测界面的极性时，与PSM相比，S-PSM似乎具有较低的极性，而NH-PSM和CH 2-PSM具有各自界面的较高极性。用胆甾三烯醇进行的荧光猝灭研究表明，所有化合物都形成了SM/胆固醇丰富的结构域。S-PSM/胆固醇和PSM/胆固醇结构域显示出相似的热稳定性，而NH-PSM/胆固醇和CH 2-PSM/胆固醇结构域的热稳定性较低。含有PSM-类似物的囊泡上的DSC显示出比PSM更复杂的熔融行为，而PSM-类似物和PSM的等摩尔混合物显示出与PSM对于NH-和S-PSM几乎理想的混合。我们的数据表明，连接磷酸胆碱头基的神经酰胺分子上的1-羟基的键的属性是重要的SM/SM和SM/胆固醇相互作用的稳定性。(C)2008 Elsevier B. V.保留所有权利。
We have characterized the molecular properties and membrane behavior of synthetically modified sphingomyelin analogues, modified on the oxygen connecting the phosphocholine group to the ceramide backbone. The oxygen was replaced with an S-atom (S-PSM), an NH-group (NH-PSM) or a CH2-group (CH2-PSM). Diphenylhexatriene and Laurdan anisotropy experiments showed that an S-linkage increased and NH- and CH2-linkages decreased the stability of PSM-analogue bilayer membranes as compared to PSM. When the polarity of the interface was probed using Laurdan, S-PSM appeared to have a lower polarity as compared to PSM whereas NH-PSM and CH2-PSM had higher polarities of their respective interfaces. Fluorescence quenching-studies with cholestatrienol showed that all compounds formed SM/cholesterol-rich domains. The S-PSM/cholesterol and PSM/cholesterol domains displayed a similar thermostability, whereas NH-PSM/ cholesterol and CH2-PSM/cholesterol domains were less thermostable. DSC on vesicles containing the PSM-analogues showed a more complex melting behavior as compared to PSM, whereas equimolar mixtures of the PSM-analogues and PSM showed almost ideal mixing with PSM for NH- and S-PSM. Our data show that the properties of the bond linking the phosphocholine head group to the 1-hydroxyl on the ceramide molecule is important for the stability of SM/SM and SM/cholesterol interactions. (C) 2008 Elsevier B.V. All rights reserved.