INSTITUTO DE INVESTIGACIONES BIOTECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Brucella cyclic β-1,2-glucans in the basic-applied research interphase
DIEGO J. COMERCI; GUIDOLIN, L. SOLEDAD; ANDRÉS E. CIOCCHINI
Congreso; 71st Annual Brucellosis Research Conference; 2018
Cyclic β-1,2-glucans (CβG) are ring-shaped periplasmic homopolysaccharides that play an important role in the interaction between bacteria and eukaryotic cells in several symbiotic and pathogenic relationships. CβG are also interesting biotechnological molecules because, due to their particular structure, they can be used for drug solubilization and stabilization, enantiomer separation, catalysis, synthesis of nanomaterial and even have immunomodulatory properties. In Brucella abortus, CβG are synthesized by a protein complex localized in the cell pole consisting of three polytopic inner membrane proteins: the CβG synthase (Cgs), the CβG transporter (Cgt) and a CβG modifier (Cgm). Cgs, the central protein of this complex, is a 320 KDa protein that catalyzes the four enzymatic reactions (initiation, elongation, phosphorolysis and cyclization) required for the synthesis and control of the degree of polymerization of CβG. Several studies performed on Cgs allowed the identification of the domains required for each enzymatic activity. Expression of Cgs-Cgt-Cgm biosynthetic complex in a specially designed E. coli resulted in a biotechnological platform able to produce a catalogue of recombinant CβG with different structures and substitutions. This platform will simplify the CβG production and purification process thus making possible the scaling up and its use in industrial applications. Furthermore, we are characterizing two carbohydrate binding domains (CBMs) in Cgs, specific for β-1,2-glucan, that may become an interesting tool to detect CβG, as there are no good antibodies to recognize CβG for in vivo and in vitro assays. Finally, we hope that the production of this catalog of recombinant glucans and CBMs allow the development of new tools to deepen the study of the structure-function relationship of the CβG in the symbiosis and pathogenesis thus generating a feedback circuit between the application and the basic research.