Chemo-enzymatic Synthesis of Pseudaminic acid glycans

PS1 Poster session 1 Odd numbers
Location (hall): 
Start/end time: 
Monday, July 1, 2019 - 15:45 to 17:15

Harriet Chidwick1, Emily Flack, Dr Martin 

1Department of Chemistry, University of York, United Kingdom

Pseudaminic acid (Pse) is a rare sugar present on the cell surface of a number of bacteria and plays a role in pathogenesis and virulence related to motility [1] and biofilm formation [2]. Pseudaminic acid processing enzymes are therefore intriguing drug targets and a potential alternative to existing antimicrobial therapies. However characterization of such enzymes are limited due to challenges in the synthesis of Pse resulting in an absence of the desired Pse chemical probes. 

The low-cost, practical synthesis of CMP-Pse has been developed utilizing enzymes from the Campylobacter jejuniand Aeromonas cavaie Pse biosynthetic pathway and progressed to the chemo-enzymatic synthesis of Pse containing di- and trisaccharides using sialyltransferases. It has also enabled investigations into the characterization and activity profile of a putative retaining pseudaminyltransferase (Figure 1).

Figure 1 Chemoenzymatic synthesis of Pse-containing saccharides; 1) PseB, PseC, PseH, PseG, PseI, Pyridoxal 5’-phosphate, ˪-glutamic acid, N-acetyl cysteamine thioacetate and phosphoenolpyruvate, 2)PseF, MgCl2and Cytidine triphosphate, 3) sialyltransferase or pseudaminyltransferase and an acceptor.

  1. C. P. Ewing, E. Andreishcheva, P. Guerry, Journal of Bacteriology 2009,191, 7086-7093.
  2. G. Soong, A. Muir, M. I. Gomez, J. Waks, B. Reddy, P. Planet, P. K. Singh, Y. Kanetko, M. C. Wolfgang, Y.-S. Hsiao, L. Tong, A. Prince, The Journal of Clinical Investigation, 116, 2297-2305