MULTISTAGE MS DISSOCIATION OF CHONDROITIN/DERMATAN SULFATE OLIGOSACCHARIDES

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 软骨素/硫酸皮肤素（CS/DS）链由通过硫酸化和差向异构化模式以组织和细胞类型特异性方式表达而分化的结构域组成。 该小组的长期目标之一是尽可能延长CS/DS链的长度，直至完整链分析结束。 我们之前已经观察到CS/DS寡糖产生的产物离子的丰度取决于存在的糖型。 这可以使用对应于CS A型（GlcA-GalNAc 4S）n、B型（IdoA-GalNAc 4S）n和C型（GlcA-GalNAc 6S）n的纯化标准品容易地确定。 通常，在串联质谱中观察到一种离子诊断每种糖型。 对于聚合度（dp）为12的寡糖，Y 3离子在CS A型中最丰富，Y 9离子在CS B型中最丰富，M-SO 3离子在CS C型中最丰富。 随着寡糖大小的增加，观察到相同的一般趋势，每种糖型的一种离子诊断。 感兴趣的是能够区分在延伸的CS/DS寡糖中存在多于一个结构域。 因此，有必要确定给定诊断产品对其敏感的结构表位。 为此，我们对dp 10 -16的CS/DS链的所有MS 2 B和Y产物离子进行MS 3。 结果表明，Y型离子的MS 3解离形成产物离子，产物离子的丰度取决于CS/DS糖型。 MS 3产物离子的模式可用于定义诊断产物离子敏感的结构表位。 B型离子生成的MS 3产物离子对CS/DS糖型的区分值要低得多。

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.