Differentiation and Quantification of Diastereomeric Pairs of Glycosphingolipids Using Gas-Phase Ion Chemistry.
Differentiation and Quantification of Diastereomeric Pairs of Glycosphingolipids Using Gas-Phase Ion Chemistry.
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DOI：
10.1021/acs.analchem.0c02755
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发表时间：
2020-10-06
影响因子：
7.4
通讯作者：
McLuckey SA
中科院分区：
文献类型：
--
作者：
Chao HC;McLuckey SA
鞘糖脂（GSLs），包括溶索鞘糖脂（lyso-GSLs）和脑苷（HexCer），构成鞘脂亚类。哺乳动物细胞中葡萄糖和半乳糖单糖头基团之间的非对映异构体，对区分它们在健康和疾病状态下的生物学作用提出了分析挑战。霰弹枪串联质谱已被证明是脂质组学分析的有力工具，其中非对异构体对GSLs的区分可以通过离线化学修饰实现。然而，由于标准的数量有限，加之对gsl的覆盖不够全面，使得对gsl的定性和定量分析变得更加复杂。在这项工作中，我们描述了一种新的策略，将霰弹枪串联质谱法与气相离子化学相结合，以实现对非对映异构体对gsl的区分和定量。简而言之，将去质子化的GSL阴离子[GSL−H]−和三吡啶-镁配合物[Mg(Terpy)2]2+依次注入并相互存储在线性离子阱中，形成电荷倒置的配合物阳离子[GSL - H + MgTerpy]+。碰撞引起的电荷反向络合阳离子的解离导致GSLs非对映体对之间的显著光谱差异，从而允许它们的区分。此外，我们还描述了一种相对定量策略，即从二元混合物中选定的诊断离子中提取归一化的%Area。所选的纯组分对lyso-GSLs和HexCer（d18:1/18:0）的分析性能也在准确性、可重复性和日间精密度方面进行了评估。纯组分可以扩展到脑苷上的不同脂肪酸链，误差有限，可以在没有所有标准的情况下相对定量非对映异构体对。我们成功地应用该方法在相对基础上对市售的猪脑总脑苷提取物中的gsl进行了鉴定和定量。
Glycosphingolipids (GSLs), including lyso-glycosphingolipids (lyso-GSLs) and cerebrosides (HexCer), constitute a sphingolipid subclass. The diastereomerism between their monosaccharide head groups, glucose and galactose in mammalian cells, gives rise to an analytical challenge in the differentiation of their biological roles in healthy and disease states. Shotgun tandem mass spectrometry has been demonstrated to be a powerful tool in lipidomics analysis, in which the differentiation of diastereomeric pairs of GSLs could be achieved with offline chemical modifications. However, the limited number of standards, as well as the lack in comprehensive coverage of the GSLs, complicates the qualitative and quantitative analysis of GSLs. In this work, we describe a novel strategy that couples shotgun tandem mass spectrometry with gas-phase ion chemistry to achieve both differentiation and quantification of the diastereomeric pairs of GSLs. In brief, deprotonated GSL anions, [GSL − H]−, and terpyridine-magnesium complex dications, [Mg(Terpy)2]2+, are sequentially injected and mutually stored in a linear ion trap to form charge-inverted complex cations, [GSL – H + MgTerpy]+. Collision-induced dissociation of the charge-inverted complex cations leads to significant spectral differences between the diastereomeric pairs of GSLs, which permits their distinction. Moreover, we describe a relative quantification strategy with the normalized %Area extracted from selected diagnostic ions in binary mixtures. Analytical performance with the selected pure-component pairs, lyso-GSLs and HexCer(d18:1/18:0), were also evaluated in terms of accuracy, repeatability, and inter-day precision. The pure-components could be extended to different fatty acyl chains on cerebrosides with limited error, which allows for the relative quantitation of the diastereomeric pairs without all standards. We successfully applied the presented method to identify and quantify, on a relative basis, the GSLs in commercially available total cerebroside extracts from the porcine brain.
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影响因子：
4.1
作者：
Li, Min;Tong, Xunliang;Liu, Huwei
通讯作者：
Liu, Huwei
影响因子：
7.4
作者：
Desaire, H;Leary, JA
通讯作者：
Leary, JA
影响因子：
4.2
作者：
Pham, Huong T.;Julian, Ryan R.
通讯作者：
Julian, Ryan R.
影响因子：
7.4
作者：
McLuckey, Scott A.;Huang, Teng-Yi
通讯作者：
Huang, Teng-Yi
影响因子：
2.3
作者：
Salpin, JY;Tortajada, J
通讯作者：
Tortajada, J