Combining FAIMS based Glycoproteomics and DIA Proteomics reveals
widespread proteome alterations in response to glycosylation occupancy
changes in N. gonorrhoeae.
Abstract
Protein glycosylation is increasingly recognized as a common protein
modification across bacterial species. Within the Neisseria genus
O-linked protein glycosylation is conserved yet closely related
Neisseria species express O-oligosaccharyltransferases (PglOs) with
distinct targeting activities. Within this work, we explore the
targeting capacity of different PglOs using Field Asymmetric Waveform
Ion Mobility Spectrometry (FAIMS) fractionation and Data-Independent
Acquisition (DIA) to allow the characterization of the impact of changes
in glycosylation on the proteome of N. gonorrhoeae. We demonstrate FAIMS
expands the known glycoproteome of wild type N. gonorrhoeae MS11 and
enables differences in glycosylation to be assessed across strains
expressing different pglO allelic chimeras with unique substrate
targeting activities. Combining glycoproteomic insights with DIA
proteomics, we demonstrate that alterations within pglO alleles have
widespread impacts on the proteome of N. gonorrhoeae. Examination of
peptides known to be targeted by glycosylation using DIA analysis
supports alterations in glycosylation occupancy occurs independently of
changes in protein levels and that the occupancy of glycosylation is
generally low on most glycoproteins. This work thus expands our
understanding of the N. gonorrhoeae glycoproteome and the roles that
pglO allelic variation may play in governing genus-level protein
glycosylation.