Applied glycomics to parasites and bacteria

ADRIANA C. CASABUONO; MALENA LANDONI; ALICIA S. COUTO

Los Cocos

Simposio; Primer Simposio Argentino de Glicobiología GlycoAR; 2014

Soc. Argentina de Q. Orgánica

In the last years, we have focused on the structural study of glycoconjugates from different microorganisms using as a main tool MALDI-TOF m.s.(matrix assisted laser desorption ionization-time of flight mass spectrometry) trying to understand different biological processes. As a first example, the structural analysis of a lipopolysaccharide isolated from Xanthomonas axonopodis pv. citri (Xac) wild type and a mutant will be described. This bacteria causes citrus canker with concomitant economical damage and the analysis was useful to understand how lipopolysaccharides from Xac function in the pathogenesis process. On the other hand, working with glycosphingolipids isolated from Plasmodium falciparum and Trypanosoma cruzi, we have developed two applications using a fluorescent group covalently linked to the lipids. The ability to tag glycoconjugates selectively with a fluorescent reporter group allows the localization and characterization of metabolites by m.s in a unique experiment providing a new method to quantify dynamic changes. Lastly, the structure of a novel type of oligosaccharide linked to Haloferax volcanii S-layer glycoprotein will be described. We showed that the glycoprotein released a novel oligosaccharide species corresponding to GlcNAc2Hex2-(SQ-Hex)6. A glyco-proteomic approach revealed N732 peptide fragments linked to the novel oligosaccharide.