Complete chemoenzymatic synthesis of the Forssman antigen using novel glycosyltransferases identified in Campylobacter jejuni and Pasteurella multocida

Abstract

We have identified an α1,4-galactosyltransferase (CgtD) and a β1,3- N -acetylgalactosaminyltransferase (CgtE) in the lipooligosaccharide (LOS) locus of Campylobacter jejuni LIO87. Strains that carry these genes may have the capa- bility of synthesizing mimics of the P blood group antigens of the globoseries glycolipids. We have also identified an α1,3-N-acetylgalactosaminyltransferase (Pm1138) from Pasteurella multocida Pm70, which is involved in the synthesis of an LOS-bound Forssman antigen mimic and represents the only known bacterial glycosyltransferase with this specificity. The genes encoding the three enzymes were cloned and expressed in Escherichia coli as soluble recombinant proteins that can be used to chemoenzymatically synthesize the Forssman antigen, and its biosynthetic precursors, in high yields. © The Author 2008. Published by Oxford University Press. All rights reserved.