Travels Through the Chemistry and Biochemistry of Mannosides

Location (hall): 
Start/end time: 
Wednesday, July 3, 2019 - 09:50 to 10:40
Speaker reference: 

Gideon Davies1

1Department of Chemistry, University Of York, York, United Kingdom

There has much discussion on social media about which sugar is the most biologically and chemically exciting.  Most people opt for the sialic acids, whilst a select group favour fucose.  Mannose, which plays myriad biological roles and whose chemistry is dominated by its axial O2 group is a strong candidate.  Mannans play key structural and recognition roles in biology and cellular function.  β-linked mannans are exemplified by robust plant structural polysaccharides, α-linked mannans form the cell wall of yeast and the core of eukaryotic N-glycans (and of the viruses that infect them). 

In this lecture I shall review some conformational aspects of mannoside enzymology with examples from α- and β-mannosidases before going on to discuss new, currently unpublished, work in three areas of mannoside chemistry: the enzymology (both mannoside phosphorylases / GDP-Man dependent mannosyltransferases) of the synthesis of β-1,2 linked mannogen in the Leishmanial parasite, the development of new activity-based probes for α-mannosidase inhibitor discovery and the unusual catalytic mechanism of N-glycan processing endomannosidases where evidence for a 1,2 anhydro “epoxide” intermediate will be discussed.