Masukawa Yoshinori, Tsujimura Hisashi, Narita Hirofumi
Tochigi Research Laboratories, Kao Corporation, Haga, Tochigi 321-0962, Japan.
J Lipid Res. 2006 Jul;47(7):1559-71. doi: 10.1194/jlr.D600007-JLR200. Epub 2006 Apr 25.
Ceramides (CERs) play key roles in signal transduction and cell regulation, probably during the keratinization of human hair. Current methods using mass spectrometry (MS), however, are not sufficient to allow the comprehensive analysis of CER molecules, including isobaric and isomeric CERs. Therefore, a method for the comprehensive profiling of CERs was developed. The method developed is based on reversed-phase liquid chromatography (RPLC) coupled to atmospheric pressure chemical ionization (APCI)-MS. Comprehensive identification and profiling of CERs is achieved using two sets of multimass chromatograms obtained from two channel detections that monitor both molecular-related and sphingoid-related ions under two different in-source collision-induced dissociation conditions and using retention times obtained from RPLC. The application of this method revealed that human hair contains 73 species of CER molecules, which were all corroborated by structural analysis using tandem mass spectrometry. The results further revealed that the composition is characterized by predominant molecules consisting of even carbon atom-containing saturated/unsaturated nonhydroxy or alpha-hydroxy fatty acids and C(18) dihydrosphingosine, a minor but distinct content of isobaric/isomeric and odd chain-containing CERs. This successfully developed RPLC-APCI-MS technique allows the comprehensive profiling of CER molecules in hair for the investigation of their physicochemical and physiological roles.
神经酰胺（CERs）在信号转导和细胞调节中发挥关键作用，可能在人类毛发角质化过程中也是如此。然而，目前使用质谱（MS）的方法不足以对CER分子进行全面分析，包括等压和异构的CERs。因此，开发了一种用于CERs全面分析的方法。所开发的方法基于反相液相色谱（RPLC）与大气压化学电离（APCI）-MS联用。通过在两种不同的源内碰撞诱导解离条件下监测分子相关离子和鞘氨醇相关离子的两个通道检测获得的两组多质量色谱图以及RPLC获得的保留时间，实现了CERs的全面鉴定和分析。该方法的应用表明，人类毛发含有73种CER分子，通过串联质谱的结构分析均得到了证实。结果进一步表明，其组成特征是主要分子由含偶数碳原子的饱和/不饱和非羟基或α-羟基脂肪酸和C(18)二氢鞘氨醇组成，还有少量但不同的等压/异构和含奇数链的CERs。这种成功开发的RPLC-APCI-MS技术能够对毛发中的CER分子进行全面分析，以研究它们的物理化学和生理作用。
