Effect of monovalent and divalent cation on the interaction of dengue virus NS3 and ssRNA

LEILA A. CABABIE; J. JEREMIAS INCICCO; LEOPOLDO G. GEBHARD; RODOLFO M. GONZÁLEZ LEBRERO; SERGIO B. KAUFMAN

Santiago del Estero

Encuentro; XLIV Reunión Anual de la Sociedad Argentina de Biofísica; 2015

Sociedad Argentina de Biofísica

Dengue virus NS3 protein is a helicase that catalyzes the hydrolysis of ATP and couples the free energy of this reaction to drive translocation on single strands and unwinding double strands of RNA. Most proteinnucleic acid interactions are extremely sensitive to the concentration of salts in solution. This is because linear nucleic acids are highly charged polyanions and as a result sequester cations in their vicinity in order to reduce the net charge on the nucleic acid. It is known that equilibrium association constant (Kobs) for protein-nucleic acid interaction decreases with increase salt concentration. Binding protein-nucleic acid is potentiated by the increase entropy originate for the ions release to free solution. In this work we studied the effect of cations on the interaction between DENV NS3 and ssRNA. We performed titration between NS3 and ssRNA at different concentrations of K+, Na+ and Mg2+ using a fluorescent RNA oligonucleotide.