TABLE 1

Inhibitory activity of NNRTIs, PFA and ddGTP against a variety of purified FIV/HIV-1 RT chimeric enzymes IC50 is the 50% inhibitory concentration or compound concentration required to inhibit the RT reaction by 50%. Poly(rC) · oligo(dG) and [3H]dGTP were used as the template/primer and radiolabeled substrate, respectively. Data are presented as the mean ± S.D. for at least two to three independent experiments. 100% FIV RT activity represents 222,250 dpm/ng protein and 100% HIV-1 RT activity represents 2,246,934 dpm/ng protein (100%).

IC50
Chimeric RT RT Activity Kmkcatd Nevirapine Efavirenz GW867420X ddGTP PFA
% pmol / μg protein / s μM
FIV66 100 2.5 0.50 >1000 >1000 >1000 0.74 ± 0.11 71 ± 32
FCH1 28 7.6 0.013 >1000 >1000 >1000 1.51 ± 0.06 >500
FCH2
FCH3
FCH4
FCH5 18.7 3.8 0.0025 >1000 >1000 >1000 0.69 ± 0.45 136 ± 27
FCH6 3.3 5.9 0.0005 >1000 >1000 >1000 1.60 ± 0.57 >500
FCH7a 1.3 6.1 >1000 >1000 >1000
FCH8a 1.9 4.5 >1000 >1000 >1000
HIV66 100 5.5 0.57 1.61 ± 0.6 0.034 ± 0.008 0.010 ± 0.002 0.08 ± 0.04 8.5 ± 5.5
HCH3
HCH4a 0.2 8.0 >1000 >1000 >1000 1.43 ± 0.27 >500
HCH6 3.2 6.7 0.018 3.0 ± 2.3 0.016 ± 0.006 0.014 ± 0.007 0.051 ± 0.007 7 ± 3
  • a The RT was not purified. The experiments were performed on 10-fold diluted bacterial RT lysates. RT activity values were expressed as a percentage of the activity found in the wild-type (purified) RT sample