Characterization of oligo- and polysialic acids by MALDI-TOF-MIS
Characterization of oligo- and polysialic acids by MALDI-TOF-MIS
复制标题
DOI：
10.1021/ac0712446
复制
发表时间：
2007-09-15
影响因子：
7.4
通讯作者：
Geyer, Hildegard
中科院分区：
文献类型：
--
作者：
Galuska, Sebastian P.;Geyer, Rudolf;Geyer, Hildegard
低聚唾液酸和聚唾液酸（oligo/polySia）的特征在于由于彼此连接的不同类型的唾液酸和所涉及的糖苷键而具有高度的多样性。考虑到目前可用于分析寡聚/聚Sia链的方法，只有荧光阴离子交换高效液相色谱（HPLC）分析、荧光C-7/C-9检测和蛋白质印迹法适用于少量材料。在这里，我们描述了一种替代技术，使用基质辅助激光解吸/电离时间-关光质谱后，对目标内酯化表征不同的唾液酸聚合物。基于MS的方法允许快速、高灵敏度和明确地鉴定天然的以及荧光标记的唾液酸聚合物，而不需要标准物质，因为精确的质量测定。具有至少100个唾液酸部分的PolySia链易于检测，此外，可以精确记录羟基的潜在修饰，例如乙酰基残基。基于不同的内酯化特征，可以区分α 2-8-和α 2-9-连接的寡聚/聚Sia。此外，该方法还可与荧光衍生化和HPLC分离相结合。
Oligo- and polysialic acids (oligo/polySia) are characterized by a high diversity in nature due to the different types of sialic acids linked to each other and gjycosidic linkages involved. Considering the methods that are presently available for analysis of oligo/polySia chains, only fluorometric anion-exchange high-performance liquid chromatography (HPLC) analysis, fluorometric C-7/C-9 detection, and western blotting are applicable to small amounts of material. Here we describe an alternative technique using matrix-assisted laser desorption/ionization time-off-light mass spectrometry after on-target lactonization to characterize different sialic acid polymers. The MS-based method allows a rapid, highly sensitive, and unambiguous identification of native as well as fluorescently labeled sialic acid polymers without the need of standard substances due to exact mass determination. PolySia chains with at least 100 sialic moieties; are easily detectable, and in addition, potential modifications of hydroxyl groups by, for instance, acetyl residues can be precisely registered. Based on different lactonization characteristics, (alpha 2-8-and (alpha 2-9-linked oligo/polySia can be distinguished. Furthermore, this method can be combined with fluorometric derivatization and HPLC separation.