title: Solid-phase methylamidation for sialoglycomics by MALDI-MS.
abstract: Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been a major approach for glycan analysis. However, the preferential cleavage of the sialic acid moiety by in- and post-source decay influences the determination of sialylated glycans by MALDI-MS. Many chemical derivatization methods were introduced to stabilize the sialylated glycan during MALDI-MS. Among current derivatization methods, methylamidation is a promising means for simultaneous analysis of natural sialylated glycans regardless of their sialic acid linkage types. Here, a novel derivatization method was developed, in which proteins were conjugated on the solid-phase support in order to stabilize the sialic acids by methylamidation and to reduce sample loss and contamination during the derivatization process. This derivatization strategy was used to investigate N-glycans from fetuin, a glycoprotein containing different types of complex N-glycans. The developed method was also applied to the N-glycan profiling of human serum from patients and healthy volunteers. Results were consistent with N-glycan profiling by HPLC-fluorescence detection. This new method provided a sensitive, simple, and robust approach for profiling glycan structures of complex samples.
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
authors.forename: Henghui
authors.initials: H
authors.lastname: Li
authors.forename: Xing
authors.initials: X
authors.lastname: Zhao
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Zhang
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Feng
authors.forename: Bi-Feng
authors.initials: BF
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
mesh_terms: D000577:Amides / Q000737:chemistry; D060748:Fetuins / Q000737:chemistry*; D006801:Humans; D008745:Methylation; D011134:Polysaccharides / Q000737:chemistry*; D012794:Sialic Acids / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000577:Amides; D060748:Fetuins; D011134:Polysaccharides; D012794:Sialic Acids