Relevance of Sulfated Sugars as Main Components of Cruzipain, the Major Cysteine Proteinase of Trypanosoma Cruzi. Synthesis of New Conjugates Sulfated Sugar - BSA

J. KOVENSKY; M. POURCELOT; M. LANDONI; L. SOPRANO; D. ACOSTA; V. G. DUSCHAK; A. S. COUTO

Tokyo-Japon

Simposio; XXV International Carbohydrate Symposium; 2010

International Carbohydrate Organization

  Chagas disease, also known as American Trypanosomiasis constitutes a major health problem in most of Latin America. The World Health Organization has estimated that some 16-18 million people are infected throughout the American continent, and that more than 100 million are exposed to the risk of infection [1]. The parasitic protozoan Trypanosoma cruzi, causative agent of the disease, contains a major cysteine proteinase, cruzipain (Cz). The presence of sulfated high-mannose type oligosaccharides in its C-terminal domain was identified as a new striking feature of this molecule [2], responsible for most antibodies in natural and experimental infections. In order to study the involvement of sulfates in immune recognition, different sulfated and non-sulfated molecules were coupled to BSA using two strategies: a) the sugar derivative was treated with ammonium carbamate and coupled through the resulting glycosylamine; b) in a few synthetic steps, a linker containing an azide group was introduced. This methodology was used for the preparation of new conjugates containing GlcNAc, GlcN6S, GlcNS, GlcNAc, and uronic acids. The sugar/protein ratio in the conjugate was determined by UV-MALDI-TOF MS. Ongoing assays using specific anti-sulfate antibodies will help to elucidate the involvement of sulfates in the antigenicity and cross reactivity of the molecule and/or in the immunopathology of Chagas disease.   [1] W.H.O. World Health Org Expert Committee. World Health Organization, Geneva, Switzerland. Tech. Rep. Ser., 905, 1-109 (2002). [2] M. Barboza, V. G. Duschak, Y. Fukuyama, H. Nonami, R. Erra-Balsells, J. J. Cazzulo, A. S. Couto, Febs J., 272, 3803-3815 (2005).   Acknowledgment: ECOS-Sud (A06S01) Argentina-France.