Congruent strategies for carbohydrate sequencing.: 1.: Mining structural details by MSn
Congruent strategies for carbohydrate sequencing.: 1.: Mining structural details by MSn
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DOI：
10.1021/ac050724z
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发表时间：
2005-10-01
影响因子：
7.4
通讯作者：
Reinhold, V
中科院分区：
文献类型：
--
作者：
Ashline, D;Singh, S;Reinhold, V
这份报告是一系列的三个重点建立一致的策略，碳水化合物测序的第一。这些报告分为（i）通过MSn分解解释小寡聚体结构的所有方面的分析考虑，（ii）使用离子片段库和相关工具进行高通量分析的数据库支持，以及（iii）根据MSn分解途径定义寡糖拓扑结构的总结算法。这第一份报告的分析贡献探讨了由离子阱质谱法暴露的结构细节的限制，样品制备为甲基衍生物和金属离子加合物进行分析。该数据挖掘工作的重点是将小寡聚体的片段与立体特异性聚糖结构相关联，该结果归因于金属离子加合和分析物构象的组合。容易的糖苷裂解引入不稳定点（吡喃糖基-1-烯），其在碰撞活化时引发随后的环断裂。产物质量和离子强度随残基间连接、支化位置和单体立体化学而变化。过度碎裂是小低聚物的性质，其中较少数量的振子内的碰撞能量通过广泛碎裂而消散。在本报告中讨论的程序统一成一个单一的战略，使用离子阱质谱仪与预期的灵敏度为电子倍增器检测。虽然已经讨论了一小部分结构，但所考虑的基本原则是完全一致的，有充分的扩展机会。
This report is the first in a series of three focused on establishing congruent strategies for carbohydrate sequencing. The reports are divided into (i) analytical considerations that account for all aspects of small oligomer structure by MSn disassembly, (ii) database support using an ion fragment library and associated tools for high-throughput analysis, and (iii) a concluding algorithm for defining oligosaccharide topology from MSn disassembly pathways. The analytical contribution of this first report explores the limits of structural detail exposed by ion trap mass spectrometry with samples prepared as methyl derivatives and analyzed as metal ion adducts. This data mining effort focuses on correlating the fragments of small oligomers to stereospecific glycan structures, an outcome attributed to a combination of metal ion adduction and analyte conformation. Facile glycosidic cleavage introduces a point of lability (pyranosyl-1-ene) that upon collisional activation initiates subsequent ring fragmentation. Product masses and ion intensities vary with inter-residue linkage, branching position, and monomer stereochemistry. Excessive fragmentation is the property of small oligomers where collisional energy within a smaller number of oscillators dissipates through extensive fragmentation. The procedures discussed in this report are unified into a singular strategy using an ion trap mass spectrometer with the sensitivity expected for electron multiplier detection. Although a small set of structures have been discussed, the basic principles considered are fully congruent, with ample opportunities for expansion.