Today’s carbohydrate session was in honor of Peter Seeberger winning the Hudson Award, with the panel of speakers reflecting Seeberger’s interests in oligosaccharide synthesis, antigens and adjuvants, and the complexities of glycosylation as a post-translational modification.
At least 4 different speakers talked in some detail about the importance of sugars in immune responses to bacteria, cancer, and disease. I think they converted me. In particular, Chi-Huey Wong and Geert-Jan Boons are finding new proteins that were either not known to be glycosylated at all or those that are specifically present/upregulated on cancer cells. Can combining these discoveries with new synthetic epitopes for generating immune responses result in the body clearing cancer cells as if they were a bacterial infection? Exciting stuff.
Todd Lowary and Ben Davis both talked a bit about the confusion of different glycoforms. For example, how do you know whether a particular structure is on the biosynthetic pathway to a second glycoform, or whether – as in the case of Lowary’s subject, lipoarabinomannan – there are more complex workings in play? Davis just seems to get around the whole thing by developing a continuous number of orthogonal reactions to allow multiple glycan incorporation in what he calls ‘post-expression mutagenesis’.
Kwan Soo Kim took us on an interesting trip through the complexities of carbohydrate synthesis, particularly as to whether substituents at the 3-, 4-, and 6-positions can affect the stereoselectivity of carbohydrate coupling at C1. Seeberger is making use of this kind of information in developing his automated carbohydrate synthesizer. He mentioned that he’s looking for users to test a beta version of the machine, so feel free to get involved!
After all that glycochemistry talk, I think it’s time for dessert.
Catherine (associate editor, Nature Chemical Biology)