... hydrogen bond donor,interacting with the carbonyl oxygen of the P4 residue on the inhibitor, or as a hydrogen bond acceptor forthe P4 NH of the inhibitor. Although some of theinhibitors were only ... recircularization. The vials were sub-jected to 1 min of melting at 95 °C, 1 min of annealing at73 °C and 15 min of extension at 72 °C in 25 cycles using athermal cycler (GeneAmp PCR system 2400, Perkin-Elmer,Boston, ... observations indicate that thehelicase can in uence protease inhibitors. Therefore,the use of truncated NS3, containing only the proteasedomain, for the identification and optimization of HCV...