Effect of CHAPS and Tween-20 on the measurement of enzymatic activity of dengue virus's NS3

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

Sierra de la Ventana

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica

The dengue virus's 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. A frequent experimental problem encountered working with enzymes is the loss of specific catalytic activity when this measurement is performed at low enzyme concentrations. Therefore we examined whether the presence of detergents in the reaction medium during activity measurements is able to overcome this difficulty. We will present experimental results which show that two detergents of different chemical nature such as CHAPS (3 - [(3-Cholamidopropyl) dimethylammonio] -1- propanesulfonate) and Tween 20 (Polyoxyethylene (20) sorbitan monolaurate) keep the catalytic activity constant regardless of the concentration enzyme used.