Protein glycosylation is increasingly recognised as an important but poorly understood aspect of microbial physiology. Although microbial protein glycosylation has been recognised for over two decades only recently has the true extend of glycosylation within microbes begun to be appreciated. A key enabler for this conceptual shift has been the development of mass spectrometry (MS) approaches which now enable the identification and characterisation of microbial glycopeptides at scale. Over the last decade my research has focused on the development of novel MS based approaches to identify as well as quantify microbial glycosylation events. By developing novel glycopeptide enrichment workflows, robust mass spectrometry methods as well as new computational tools for identifying glycopeptides this work has revealed microbial glycosylation is far more widespread then initially thought.
Using MS approaches, we have characterised a range of microbial glycosylation systems across bacterial genera including Campylobacter, Acinetobacter, Burkholderia, Salmonella and Escherichia. Across these systems our MS approaches have enabled us to characterise the glycans install by these systems, their glycan specificities as well as their protein substrates. These proteins substrates are not limited to bacterial proteins with our approaches also able to identify glycosylation events mediated by bacterial enzymes of host proteins during bacterial infections. By coupling glycoproteomics with quantitative proteomics this has also enabled us to shed light on the impacts of glycosylation on bacterial and host proteomes revealing that glycosylation can profoundly modulate protein stability, interactions and functions.
Excitingly the techniques developed to study bacterial glycosylation are now finding broader utility enabling the study of other unusual forms of glycosylation such as C-glycosylation. Combined this work has demonstrated that MS approaches have now become an indispensable tool for the elucidation and tracking of microbial glycosylation events in a high-throughput manner.