Human serum N-linked intact glycopeptides LC-MS/MS

ABSTRACT: Large-scale identification of N-linked intact glycopeptides by liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) in human serum is challenging due to the wide dynamic range of serum protein abundances, the lack of a complete serum N-Glycan database and the existence of non-specifically digested peptides and numerous modifications. In this regard, a spectral library search method was presented for serum N-linked intact glycopeptides identification with target-decoy and motif-specific false discovery rate (FDR) control. Low-abundant glycoproteins were firstly separated from high-abundant proteins by acetonitrile (ACN) precipitation. After digestion, the N-linked intact glycopeptides were enriched by hydrophilic interaction liquid chromatography (HILIC) column and a portion of the enriched N-linked intact glycopeptides were processed by N-Glycosidase F (PNGase F) to generate de-glycopeptides. Both N-linked intact glycopeptides and de-glycopeptides were analyzed by LC-MS/MS. From N-linked de-glycopeptides datasets, 764 N-linked glycoproteins, 1,699 N-linked glycosites and 3,328 unique N-linked de-glycopeptides were identified. The spectra of these N-linked de-glycopeptides were utilized for N-linked de-glycopeptides library construction and identification of N-linked intact glycopeptides. Four types of N-linked glycosylation motifs (NXS/T/C/V, X≠P) were used to recognize the N-linked de-glycopeptides, and two different N-Glycan mass databases including 27 modified N-Glycan masses and 712 unmodified N-Glycan masses were combined and utilized during spectral library search for identification of N-linked intact glycopeptides. In total, from the N-linked intact glycopeptides datasets, 526 N-linked glycoproteins, 1,036 N-linked glycosites, 22,677 N-linked intact glycopeptides and 738 N-Glycan masses were identified under 1% FDR, representing the most in-depth serum N-glycoproteome identified by LC-MS/MS at N-linked intact glycopeptide level and N-linked de-glycopeptides level.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human) Gallus Gallus (chicken) Armoracia Rusticana

TISSUE(S): Blood Serum

SUBMITTER: Lian Shu  

LAB HEAD: Fuquan Yang

PROVIDER: PXD015622 | Pride | 2020-04-21

REPOSITORIES: Pride