Figure 4:

ITBA analogs inhibit in vitro NS3 RNA unwinding activity. A) Unwinding of 2 nM of radiolabeled duplex RNA by 500 nM of recombinant NS3 in the presence of 25 µM of the indicated ITBA analogs. A contaminating duplex RNA species indicated by an asterisk (*) was disregarded in the evaluation of the helicase activity (see text and Supplemental data). Representative gels from triplicate measurements. B) Quantitation of the radioactivity for time points of triplicate experiments were averaged and fit to a single exponential to calculate the following RNA unwinding rate constants: DMSO control (red squares): 1.84 ± 0.19 min⁻¹, Analog 14 (blue triangles): 1.81 ± 0.77 min⁻¹, Analog 16 (green inverted triangles): 2.38 ± 0.72 min⁻¹, and Analog 19 (black diamonds): 2.14 ± 0.69 min^-1.