Unraveling glycosyltransferases involved in the biosynthesis of galactose and N-acetylglucosamine-containing glycoconjugates of the protozoan parasite Trypanosoma brucei
Final Report Abstract
This research fellowship allowed me to work on a family of putative glycosyltransferase (GT) genes in the parasitic protozoan organism Trypanosoma brucei, the causative agent of human African trypanosomiasis or sleeping sickness. Using GT null and conditional mutants of the parasite, I have characterised the biochemical defects in protein glycosylation by mass spectrometry and lectin blotting, and interpreted these data with respect to the biochemical function of the encoded GTs. I have confirmed these predictions by expressing the GT enzymes and performing substrate-specificity experiments using synthetic glycan acceptor substrates and nucleotide sugar donor substrates. A comprehensive product characterisation was possible with the help of both radiochemical/chromatographic and mass spectrometric methods. Thereby, I identified the two N-acetylglucosaminyltransferases that are required for the biosynthesis of complex N-glycans in T. brucei, TbGnTI and TbGnTII. My studies revealed significant differences between the parasite enzymes and their metazoan counterparts in both amino acid sequence and substrate specificity, emphasising the highly divergent nature of the trypanosome genes involved in structurally-conserved aspects of complex N-glycan biosynthesis.
Publications
- “Identification and functional characterization of a highly divergent N-acetylglucosaminyltransferase I (TbGnTI) in Trypanosoma brucei.” J Biol Chem. 2014 Mar 28;289(13):9328-39
Damerow M, Rodrigues JA, Wu D, Güther ML, Mehlert A, Ferguson MA
(See online at https://doi.org/10.1074/jbc.M114.555029) - “A gene of the β3- glycosyltransferase family encodes N-acetylglucosaminyltransferase II function in Trypanosoma brucei.” J Biol Chem. 2016 May 4
Damerow M, Graalfs F, Güther ML, Mehlert A, Izquierdo L, Ferguson MA
(See online at https://doi.org/10.1074/jbc.M116.733246)
