title: A new method for quantitative analysis of cell surface glycoproteome.
abstract: As the altered glycosylation expressions of cell surface proteins are associated with many diseases, glycoproteomics approach has been widely applied to characterization of surface glycosylation alteration. In general, the abundances of proteolytic glycopeptides derived from corresponding glycoproteins can be measured to determine the abundances of glycoproteins. However, this quantification strategy cannot distinguish whether the changes are results from changes of protein abundance or changes in glycosite occupancy. For the accurate and specific quantification of the cell surface glycosylation profile, we proposed a modified cell surface-capturing strategy where the glycopeptides were submitted to LC-MS/MS analysis directly for identification of glycoproteins and the non-glycopeptides were isotopically labelled for quantification of glycoproteins. This strategy was applied to comparatively analyze cell surface glycoproteins of two human cell lines, i.e. Chang Liver and HepG2 cells. Totally 341 glycoproteins were identified with 82.4% specificity for cell membrane proteins and 33 glycoproteins were quantified with significant expression change between the two cell lines. The differential expressions of two selected proteins (EMMPRIN and BCAM) were validated by Western blotting. This method enables specific and accurate analysis of the cell surface glycoproteins and may have broad application in the field of biomarker and drug target discovery.
authors.affiliation: Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Sun
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.forename: Kai
authors.initials: K
authors.lastname: Cheng
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liu
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Qin
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D051926:Basigin / Q000737:chemistry / Q000378:metabolism; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006020:Glycopeptides / Q000032:analysis / Q000737:chemistry; D056945:Hep G2 Cells / Q000737:chemistry; D006801:Humans; D008188:Lutheran Blood-Group System / Q000737:chemistry / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods*
chemical_list: C090228:BCAM protein, human; C497886:BSG protein, human; D015815:Cell Adhesion Molecules; D006020:Glycopeptides; D008188:Lutheran Blood-Group System; D008562:Membrane Glycoproteins; D020543:Proteome; D051926:Basigin