N-AcetylGlucosamine (GlcNAc) derived oligo- and polysaccharides participate in many biological important structures. Chitin (GlcNAc polysaccharide) is the main structural component of insect and crustaceans exoskeleton and is present in the cell wall of fungus and other microorganism, bacterial cell walls are made of peptidoglycan that has its glycan core chain built with GlcNAc related units (GlcNAc-muramyl disaccharides). N-glycan chains of eukaryotic glycoproteins have chitobiose at its core structure. Quite diverse proteins recognize those chitooligosaccharide related structures accomplishing functions as, for example, defense proteins (hevein domains), symbiosis signal recognition (Lys-M domains), carbohydrate processing (chitinases, glucosaminidases) etc. In our laboratory we are developing and applying NMR methodologies for studying those interactions in model systems based on hevein1 and Lys-M domains in presence of chitooligosaccharides2 of different size or chemically modified analogues and synthetic N-glycan chains3. The binding epitope on the oligosaccharide-ligand structures and some key driving forces for those interactions as carbohydrate-aromatic (CH-Pi)4 and hydrogen bonds have been characterized thermodynamically and structurally at atomic level.
1)- J. Jimenez-Barbero, F. J. Cañada, J. L. Asensio, N. Aboitiz, P. Vidal, A. Canales, P. Groves, H. J. Gabius & H. C. Siebert; Adv. Carbohydr. Chem. Biochem, 2006, 60: 303-354
2)-M. A. Morando, A. Nurisso, N. Grenouillat, B. Vauzeilles, J. M. Beau, F. J. Cañada, J. Jimenez-Barbero & A. Imberty; Glycobiology, 2011, 21(6), 824-33
3)-A. Ardá, P. Blasco, D. Varón Silva, V. Schubert, S. André, M. Bruix, F. J. Cañada, H. J. Gabius, C. Unverzagt, J. Jiménez-Barbero.; J. Am. Chem. Soc. 2013, 135(7):2667-75.
4)-J. L. Asensio, A. Arda, F. J. Cañada & J. Jimenez-Barbero; Acc. Chem. Res. 2012, DOI: 10.1021/ar300024d
Acknowledgments:
Financial support from the Ministry of Economy and Competitiveness of Spain (Grants CTQ2009-08536, and CTQ2012-30820) is acknowledged
