Morrison Kelsey A, Bendiak Brad K, Clowers Brian H
Department of Chemistry, Washington State University, PO Box 644630, Pullman, WA, 99164, USA.
Department of Cell and Developmental Biology and Program in Structural Biology and Biochemistry, University of Colorado Health Sciences Center, Mail Stop 8108, 12801 E 17th Ave., Aurora, CO, 80045, USA.
J Am Soc Mass Spectrom. 2017 Apr;28(4):664-677. doi: 10.1007/s13361-016-1505-y. Epub 2016 Oct 28.
Using five isomeric tetrasaccharides in combination with seven multivalent metals, the impact on mobility separations and resulting CID spectra were examined using a hybrid ion mobility atmospheric pressure drift tube system coupled with a linear ion trap. By enhancing the duty cycle of the drift tube system using a linearly chirped frequency, the collision-induced dissociation spectra were encoded in the mobility domain according to the drift times of each glycan isomer precursor. Differential fragmentation patterns correlated with precursor drift times ensured direct assignment of fragments with precursor structure whether as individual standards or in a mixture of isomers. In addition to certain metal ions providing higher degrees of separation than others, in select cases more than one arrival time distribution was observed for a single pure carbohydrate isomer. These observations suggest the existence of alternative coordination sites within a single monomeric species, but more interesting was the observation of different fragmentation ion yields for carbohydrate dimers formed through metal adduction. Positive-ion data were also compared with negative-ion species, where dimer formation did not occur and single peaks were observed for each isomeric tetrasaccharide-alditol. This enhanced analytical power has implications not only for carbohydrate molecules but also for a wide variety of complex mixtures of molecules where dissociation spectra may potentially be derived from combinations of monomeric, homodimeric, and heterodimeric species having identical nominal m/z values. Graphical Abstract ᅟ.
使用五种同分异构四糖与七种多价金属相结合，利用耦合线性离子阱的混合离子迁移率大气压漂移管系统，研究了对迁移率分离及所得碰撞诱导解离（CID）光谱的影响。通过使用线性啁啾频率提高漂移管系统的占空比，碰撞诱导解离光谱根据每种聚糖同分异构体前体的漂移时间在迁移率域中进行编码。与前体漂移时间相关的差异碎裂模式确保了无论作为单个标准品还是异构体混合物，都能直接将碎片与前体结构进行关联。除了某些金属离子比其他金属离子提供更高程度的分离外，在某些情况下，对于单一纯碳水化合物同分异构体观察到了不止一种到达时间分布。这些观察结果表明在单个单体物种中存在替代配位位点，但更有趣的是观察到通过金属加成形成的碳水化合物二聚体的不同碎裂离子产率。正离子数据也与负离子物种进行了比较，在负离子物种中未发生二聚体形成，并且每种同分异构四糖 - 糖醇均观察到单峰。这种增强的分析能力不仅对碳水化合物分子有影响，而且对各种各样的复杂分子混合物也有影响，在这些混合物中，解离光谱可能潜在地源自具有相同标称质荷比的单体、同二聚体和异二聚体物种的组合。图形摘要ᅟ。
