Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education , Institute for Interdisciplinary Research, Institute of Environment and Health, Jianghan University , Wuhan 430056 , China.
State Key Laboratory of Environmental Chemistry and Ecotoxicology , Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , 18 Shuangqing Road , Haidian District, Beijing 100085 , China.
Anal Chem. 2019 Feb 19;91(4):2744-2751. doi: 10.1021/acs.analchem.8b04420. Epub 2019 Feb 5.
Sialic acid is a family of N- and O-substitutions of neuraminic acid. Plasma or serum sialic acid has been established as a potential disease marker. For example, the presence of 9- O-acetyl on the sialic acid of some glycans and glycoconjugates (e.g., 9- O-acetyl GD3 ganglioside) could be related to cancer occurrence. A variety of assays are available to measure serum or plasma sialic acid; however, sample preparation and storage can alter the O-acetylation profile due to the loss of O-acetyl groups and/or the migration of O-acetyl groups. Herein, we report dried blood spot (DBS) sampling, in combination with diamino-4,5-methylenedioxybenzene derivatization, for profiling sialic acids in blood samples with minimal alteration in O-acetylation patterns. The feasibility of the method was first evaluated by analyzing sialic acids in crucian carp blood and comparing with traditional blood/plasma sample preparation procedures. A total of 19 different sialic acids were identified by using liquid chromatography-Orbitrap mass spectrometry, including four mono-O-acetylated N-acetylneuraminic acids, four mono-O-acetylated N-glycolylneuraminic acids, six di-O-acetylated N-acetylneuraminic acids, and three tri-O-acetylated N-acetylneuraminic acids. The long-term storage study indicated that DBS sampling could effectively preserve the O-acetylation information for at least 6 weeks. Thus, it is demonstrated that this method is a valuable tool for the study of sialic acid diversity, especially for the characterization of isomeric structures.
唾液酸是神经氨酸的 N-和 O-取代基家族。血浆或血清唾液酸已被确立为一种潜在的疾病标志物。例如，某些糖链和糖缀合物（例如，9-O-乙酰基 GD3 神经节苷脂）上唾液酸的 9-O-乙酰基的存在可能与癌症的发生有关。有多种测定方法可用于测量血清或血浆唾液酸；然而，由于 O-乙酰基的丢失和/或 O-乙酰基的迁移，样品制备和储存会改变 O-乙酰化模式。在此，我们报告了干血斑（DBS）采样，结合二氨基-4,5-亚甲二氧基苯衍生化，用于最小化 O-乙酰化模式变化的血液样本中唾液酸的分析。该方法的可行性首先通过分析鲫鱼血液中的唾液酸并与传统的血液/血浆样品制备程序进行比较来评估。使用液相色谱-Orbitrap 质谱法共鉴定出 19 种不同的唾液酸，包括四种单-O-乙酰化 N-乙酰神经氨酸、四种单-O-乙酰化 N-羟乙酰神经氨酸、六种二-O-乙酰化 N-乙酰神经氨酸和三种三-O-乙酰化 N-乙酰神经氨酸。长期储存研究表明，DBS 采样可有效保存 O-乙酰化信息至少 6 周。因此，证明该方法是研究唾液酸多样性的有价值的工具，特别是对同构结构的表征。
