Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
International Graduate Program of Molecular Science and Technology, National Taiwan University (NTU-MST), Taipei 10617, Taiwan.
Anal Chem. 2023 Jun 13;95(23):8789-8797. doi: 10.1021/acs.analchem.2c05599. Epub 2023 May 26.
-linked glycosylation is one of the most important post-translational modifications of proteins. Current knowledge of multicellular eukaryote -glycan biosynthesis suggests high mannose -glycans are generated in the endoplasmic reticulum and Golgi apparatus through conserved biosynthetic pathways. According to conventional biosynthetic pathways, four ManGlcNAc isomers, three ManGlcNAc isomers, and one ManGlcNAc isomer are generated during this process. In this study, we applied our latest mass spectrometry method, logically derived sequence tandem mass spectrometry (LODES/MS), to re-examine high mannose -glycans extracted from various multicellular eukaryotes which are not glycosylation mutants. LODES/MS identified many high mannose -glycan isomers previously unreported in plantae, animalia, cancer cells, and fungi. A database consisting of retention time and CID MS mass spectra was constructed for all possible ManGlcNAc ( = 5, 6, 7) isomers that include the isomers by removing arbitrary numbers and positions of mannose from canonical -glycan, ManGlcNAc. Many -glycans in this database are not found in current -glycan mass spectrum libraries. The database is useful for rapid high mannose -glycan isomeric identification.
糖基化是蛋白质翻译后修饰的重要方式之一。目前对真核生物糖基化生物合成的认识表明，高甘露糖聚糖在内质网和高尔基体中通过保守的生物合成途径产生。根据传统的生物合成途径，在此过程中会产生四种 ManGlcNAc 异构体、三种 ManGlcNAc 异构体和一种 ManGlcNAc 异构体。在这项研究中，我们应用了最新的质谱方法，即逻辑推导序列串联质谱（LODES/MS），重新检测了来自各种真核生物（非糖基化突变体）的高甘露糖聚糖。LODES/MS 鉴定出了许多以前在植物界、动物界、癌细胞和真菌中未报道过的高甘露糖聚糖异构体。为所有可能的 ManGlcNAc（=5、6、7）异构体构建了一个包含从经典聚糖 ManGlcNAc 中任意数量和位置去除甘露糖的异构体的保留时间和 CID MS 质谱数据库。该数据库中的许多聚糖在当前的聚糖质谱文库中未找到。该数据库可用于快速鉴定高甘露糖聚糖异构体。
