Li Zhucui, Zhang Qibin
Center for Translational Biomedical Research, University of North Carolina at Greensboro, North Carolina Research Campus, Kannapolis, NC, 28081, USA.
Department of Chemistry & Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, 27412, USA.
Anal Bioanal Chem. 2021 May;413(12):3269-3279. doi: 10.1007/s00216-021-03262-2. Epub 2021 Mar 8.
Gangliosides are ubiquitously present on cell surface. They are more abundantly expressed in nerve cells and tissues and involved in pathology of various diseases. Diversity of molecular structures in the carbohydrate head group, fatty acyl, and long chain base increases the complexity of analyzing gangliosides. In this study, an ultrahigh-performance liquid chromatography-tandem mass spectrometry method is developed for analysis of the co-eluting ganglioside isomers, which uses ion polarity switching to integrate glycan head isomer identification, ceramide isomer differentiation, and quantification of ganglioside into one analysis. The method is facilitated with an extensive ganglioside target list by combining the various glycan head groups, long chain bases, and the experimentally determined fatty acyls. Correlation between the retention time of ganglioside and its ceramide total carbon number is experimentally validated and used to predict retention time of ganglioside target list for scheduling the final multiple reaction monitoring method. This method was validated according to the FDA guidelines: 96.5% of gangliosides with good accuracy (80-120%), precision (< 15%), and linearity R > 0.99. The authenticated gangliosides were quantified from mouse brain by isotope dilution. Overall, 165 gangliosides were quantified using 10 mg mouse brain tissue, including 100 isomers of GM1, GM2, GM3, GD1a, GD1b, GD2, GD3, and GT1b.
神经节苷脂普遍存在于细胞表面。它们在神经细胞和组织中表达更为丰富，并参与多种疾病的病理过程。碳水化合物头部基团、脂肪酰基和长链碱基的分子结构多样性增加了分析神经节苷脂的复杂性。在本研究中，开发了一种超高效液相色谱 - 串联质谱法用于分析共洗脱的神经节苷脂异构体，该方法利用离子极性切换将聚糖头部异构体鉴定、神经酰胺异构体区分以及神经节苷脂定量整合到一次分析中。通过结合各种聚糖头部基团、长链碱基和实验测定的脂肪酰基，该方法借助广泛的神经节苷脂目标列表得以实现。实验验证了神经节苷脂保留时间与其神经酰胺总碳原子数之间的相关性，并用于预测神经节苷脂目标列表的保留时间，以安排最终的多反应监测方法。该方法根据美国食品药品监督管理局（FDA）指南进行了验证：96.5%的神经节苷脂具有良好的准确度（80 - 120%）、精密度（< 15%）和线性（R > 0.99）。通过同位素稀释对从小鼠脑中鉴定出的神经节苷脂进行定量。总体而言，使用10毫克小鼠脑组织对165种神经节苷脂进行了定量，包括GM1、GM2、GM3、GD1a、GD1b、GD2、GD3和GT1b的100种异构体。
