Separation and quantification of sn-1 and sn-2 fatty acid positional isomers in phosphatidylcholine by RPLC-ESIMS/MS
Separation and quantification of sn-1 and sn-2 fatty acid positional isomers in phosphatidylcholine by RPLC-ESIMS/MS
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DOI：
10.1093/jb/mvp171
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发表时间：
2010-02-01
影响因子：
2.7
通讯作者：
Taguchi, Ryo
中科院分区：
文献类型：
--
作者：
Nakanishi, Hiroki;Iida, Yasuhiro;Taguchi, Ryo
生物膜中的内源性磷脂酰胆碱以异构体形式存在，其酰基部分位于甘油主链的 sn-1 或 sn-2 位置。然而，通常无法获得这些位置异构体的详细生化信息。本研究是第一篇利用反相 LC-ESIMS/MS 分离和鉴定内源性磷脂酰胆碱位置异构体的报告。 PC 中位置异构体的分离是通过使用高分辨率 HPLC 系统的超高效 LC 实现的。为了鉴定各个 PC 物种中的位置异构体，使用了通过负离子模式下 MS/MS 分析获得的溶血 PC 相关片段和脂肪酸。从生物样品的应用结果来看，小鼠大脑的脂质提取物中甘油骨架的sn-1位置富含含有22:6的PC。然而，小鼠心脏和肝脏的脂质提取物中位置异构体并不丰富。这一成就表明，不同组织或分子种类中位置异构体的相对量是不同的。这些结果将有助于阐明磷脂酶和酰基转移酶等重塑酶的生物学机制。因此，我们的报告为理解磷脂的分子组成及其生物学作用提供了一个新颖且重要的里程碑。
Endogenous phosphatidylcholine in biological membranes exists as isomers with acyl moieties at the sn-1 or sn-2 positions of the glycerol backbone. However, detailed biochemical information on these positional isomers is not generally available. This study is the first report on the separation and identification of positional isomers of endogenous phosphatidylcholine using reversed-phase LC-ESIMS/MS. The separation of positional isomers in PC was achieved by using ultra performance LC, which uses a high-resolution HPLC system. To identify positional isomers in individual PC species, their lyso-PC-related fragments and fatty acids, which were obtained by MS/MS analysis in the negative ion mode, were used. From the application results of biological samples, the lipid extracts of mouse brain were found to be abundant in PC containing 22:6 at the sn-1 position of the glycerol backbone. However, the lipid extracts from mouse heart and liver were not abundant in positional isomers. This achievement demonstrates that the relative amounts of positional isomers in various tissues or molecular species differ. These results will be useful for the clarification of the biological mechanisms of remodelling enzymes such as phospholipase and acyltransferase. Thus, our report provides a novel and critical milestone in understanding how molecular composition of phospholipids is established and their biological roles.