LC-MSN METHOD FOR QUALITATIVE & QUANTITATIVE ANALYSIS OF COMPLEX LIPID MIXTURES

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 虽然纳米质谱仪是表征简单脂类混合物(1，2)的一个很好的选择，但对于高度复杂的样品的定性和定量分析往往是不够的。所描述的大多数分离方法都是有限的，因为它们要么只针对感兴趣的特定类别(3)，要么不适合于MS，这是一种更好的检测方法，特别是对于少量样品的分析。我们之前开发了一种简单、可重复性的三步法，通过采用文献中描述的分离系统来进行脂类分析(4，5，6)。经过一次可选的初始分级后，正相高效液相色谱-质谱仪首先提供分类分离，然后反相LC-MS/MS系统回答剩余的问题。将分离提取的低密度脂蛋白和脂类标准品用一维或二维液相色谱分离，并以正、负离子模式进行质谱仪检测。使用两种不同的梯度来分离多非极性和多极性的脂类。量化是基于这一步骤的。我们现在正在使用UPLC简化这种方法。使用QStar QoTOF MS或LTQ-Orbitrap MS或纳米级MS/MS和/或前驱体离子扫描对馏分进行了LC-MS/MS表征。含有不同非极性、磷脂和糖脂的脂类和糖脂标准品已根据极性被重复分离。当用于生物样品时，这一步骤也用于保护下面的柱，但并不总是必要的。量化的准确性在很大程度上取决于可用的内部和外部标准的质量。该系统正被应用于与普鲁恩病毒相关的脂类的分析，以及从母乳中显示出抗艾滋病毒活性的硫脂部分。 1)M.Puffer和R.C.Murphy(2003)。质谱学评论22,332-。 2)X.Han.和R.W.Gross(2005)。质谱学版本24,367-412。 3)R.C.墨菲等人。(2001年)。化学。第101版，479-526号。 4)J.Hamilton和K.Comai(1988)。脂23、1046-49和1150-53。 5)W.W.克里斯蒂等人。(1995年)。J.高分辨率。变色剂。18，97-100。 6)F.K.韦尔蒂等人。(1991年)。J·克莱恩。投资。87年，1748-1754年。 7)U·Sommer等人。(2006)J.Lipid Res.47,804-814.

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. While nanospray MS is a good choice for the characterization of simple lipid mixtures (1,2), it is often not sufficient for the qualitative and quantitative analysis of highly complex samples. Most separation methods described are limited, in that they either target only specific classes of interest (3), or are not well suited for MS, the superior detection method, especially for analyses of small amounts of samples. We previously developed a simple, reproducible three-step method for lipid analysis by adapting separation systems described in the literature for the chromatography of lipids (4,5,6). After an optional initial fractionation, normal phase HPLC-MS first provided class separation and then a reversed phase LC-MS/MS system answered remaining questions. Isolated and extracted LDL lipids and lipid standards were separated by 1D or 2D LC and detected by mass spectrometry in positive and negative ion modes. Two different gradients were used for the separation of more nonpolar and more polar lipids. Quantification was based on this step. We are now simplifying this method using UPLC. Fractions are characterized by LC-MS/MS using athe QStar QoTOF MS, or LTQ-Orbitrap MS, or by nanospray MS/MS and/or precursor ion scanning. Lipid and glycolipid standards containing diverse nonpolar, phospho- and glycolipids have been reproducibly separated on the basis of polarity. This step, when used for biological samples, also serves to protect the following column, but is not always necessary. The accuracy of the quantification depends mostly on the quality of internal and external standards available. The system is being applied to the analysis of lipids associated with prions and to sulfatide fractions from human milk that show anti-HIV acrivity. 1) M. Puffer and R.C. Murphy (2003). Mass Spectrometry Reviews 22, 332-64. 2) X. Han and R.W. Gross (2005). Mass Spectrom Rev. 24, 367-412. 3) R.C. Murphy et al. (2001). Chem. Rev. 101, 479-526. 4) J. Hamilton, and K. Comai (1988). Lipids 23, 1046-49 & 1150-53. 5) W.W. Christie et al. (1995). J. High Resol. Chromatogr. 18, 97-100. 6) F.K. Welty et al. (1991). J. Clin. Invest. 87, 1748-1754. 7) U. Sommer et al. (2006) J. Lipid Res. 47, 804-814.