MULTISTAGE MS DISSOCIATION OF CHONDROITIN/DERMATAN SULFATE OLIGOSACCHARIDES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 软骨素/硫酸皮肤素(CS/DS)链由以组织和细胞类型特异性方式表达的硫酸盐化和异构化模式区分的结构域组成。该小组的长期目标之一是尽可能延长CS/DS链的长度，接近完整链分析的结束。我们已经观察到，CS/DS寡糖产生的产物离子的丰度取决于存在的糖形式。这可以容易地使用对应于CS型A(GLCA-GalNAc4S)n、B型(IDOA-GalNAc4S)n和C型(GLCA-GalNAc6S)n的纯化标准来确定。通常，在串联质谱图中观察到每个糖形的一个离子诊断。对于聚合度(DP)12的低聚糖来说，Y3离子对于CSA型是最丰富的，Y9离子对于B型是最丰富的，M-SO3离子对于C型是最丰富的。随着低聚糖大小的增加，观察到相同的一般趋势，每个糖型都有一个离子诊断。人们感兴趣的是能够区分扩展的CS/DS寡糖中存在的多个结构域。因此，有必要确定特定诊断产品对哪些结构表位敏感。为此，我们对dp10-16的CS/DS链的所有MS2B和Y乘积离子进行了MS3处理。结果表明，Y型离子的MS3解离形成产物离子，其丰度依赖于CS/DS糖型。MS3产物离子的模式对于定义诊断产物离子对其敏感的结构表位是有用的。由B型离子产生的MS3产物离子对CS/DS糖型的判别力要小得多。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Chondroitin/dermatan sulfate (CS/DS) chains consist of domains differentiated by sulfation and epimerization patterns expressed in a tissue and cell-type specific manner. One of the long term goals in the group has been to extend the length of the CS/DS chains as far as possible, toward the end of intact chain analysis. We have observed previously that the abundances of product ions generated from CS/DS oligosaccharides depends on the glycoforms present. This may readily be determined using purified standards corresponding to CS type A (GlcA-GalNAc4S)n, type B (IdoA-GalNAc4S)n and type C (GlcA-GalNAc6S)n. Typically, one ion diagnostic for each glycoform is observed in a tandem mass spectrum. For a degree of polymerization (dp) 12 oligosaccharide, the Y3 ion is most abundant for CS type A, the Y9 ion for type B and the M-SO3 ion for type C. As the size of the oligosaccharide increases, the same general trend is observed with one ion diagnostic for each glycoform. It is of interest to be able to differentiate the presence of more than one structural domain in an extended CS/DS oligosaccharide. Thus, it is necessary to determine the structural epitopes to which a given diagnostic product are sensitive. Towards this end, we subjected all MS2 B and Y product ions to MS3 for CS/DS chains of dp10-16. The results showed that MS3 dissociation of Y-type ion formed product ions the abundances of which depended on the CS/DS glycoform. The pattern of MS3 product ions was useful for defining the structural epitopes to which the diagnostic product ions are sensitive. The MS3 product ions generated from B-type ions showed far less discriminatory value for CS/DS glycoforms.