Grant: Research Tools and Instruments

Glycans regulate various cellular processes in all kingdoms of life, and understanding how specific sugars affect the function of the glycoproteins or glycolipids in which they reside is a fundamental question in glycobiology. The glycans produced by bacteria are highly heterogeneous and comprise unusual sugars important to bacterial physiology but whose synthesis pathways remain hypothetical. The overarching aim of our NSERC-funded research is to elucidate the biosynthesis pathways of novel bacterial sugars to better understand how they contribute to the function of glycosylated macromolecules and provide molecular tools necessary for future study of the mechanisms of assembly of complex glycans. Specifically, we have been investigating the biosynthesis and function of novel modified heptoses using Yersinia pseudotuberculosis and Campylobacter jejuni as model systems. While genome data suggest that modified heptoses are also present in other bacteria, their function is often unknown. Our enzymology studies showed that these modified heptoses stem from the precursor GDP- manno -heptose by catalysis by highly specific sugar-nucleotide modifying enzymes (SNMEs). Our 8 publications about the synthesis and biological function of their surface sugars attest that we have developed a unique expertise which positioned our group as a leader in glycobiology. This work has led to numerous national and international collaborations and presentations and has involved 9 graduate students, 13 honors students, and ~15 summer students since its beginning (not accounting for students working on health-related issues). All our enzymology work relies on the use of capillary electrophoresis to separate and detect closely related sugar derivatives as they arise from modification of precursor substrates by various SNMEs. The technique is very robust while extremely sensitive and allows analyses at the micro- to nano-scale level, an essential feature considering that all reactions involve extremely precious sugar-nucleotides that we have to generate in situ from very expensive precursors. Our current CE machines purchased in 2001 and 2005 are worn out, with frequent and costly break downs that impede our productivity. The supplier will not service these old models nor supply spare parts as off end of 2018. Thus this proposal is to allow the replacement of one of our CE instruments by a newer, more performant system to support our glycobiology research under optimal conditions without compromising our productivity in this competitive field. We have selected the Sciex PACE-MDQ Plus instrument which will support our PDF, MSc and honors students activities initially, the next generation of PACE-MDQ systems we have been using until now and have proven very robust and efficient.