Site-specific O-Glycosylation Analysis of Human Blood Plasma Proteins

ABSTRACT: Here, we report on the site-specific O-glycosylation analysis of human blood plasma glycoproteins. To this end pooled human blood plasma of healthy donors was digested non-specifically using Protein-ase K, followed by a precipitation step, as well as a glycopeptide enrichment and fractionation step via hydrophilic interaction liquid chromatography. Enriched glycopeptide fractions were subjected to mass spectrometric analysis using reversed-phase liquid chromatography coupled online to an ion trap mass spectrometer operated in positive-ion mode. Peptide identity and glycan composition were derived from low-energy collision-induced dissociation fragment spectra acquired in multistage mode. To pinpoint the O-glycosylation sites glyco�peptides were fragmented using electron transfer dissociation. Spectra were annotated by database searches as well as manually. Overall, 31 O-glycosylation sites and regions belonging to 22 proteins were identified. The majority of these proteins were acute-phase proteins. Strikingly, also 11 novel O-glycosylation sites and regions were identified. In total 23 O-glycosylation sites could be pinpointed. Interestingly, the use of Proteinase K proved to be particularly beneficial in this context. The identified O-glycan compositions most probably correspond to mono- and disialylated core-1 mucin-type O-glycans (T-antigen).

INSTRUMENT(S): amaZon ETD

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Marcus Hoffmann, Kristina Marx, Udo Reichl, Manfred Wuhrer, Erdmann Rapp 

PROVIDER: MSV000079141 | MassIVE | Fri Jun 05 12:39:00 BST 2015

SECONDARY ACCESSION(S): PXD003270

REPOSITORIES: MassIVE