Table 3. Results from a multinuclear-activation galactosidase indicator assay indicate that PA-457 blocks late in the virus life cycle.
| Inhibitor | % Decrease (β-galactosidase) |
|---|---|
| DMSO | 0 |
| T20 | 98 |
| AZT | 82 |
| Nevirapine | 85 |
| Indinavir | 10 |
| PA-457 | 12 |
The entry inhibitor T20 and the RT inhibitors AZT and nevirapine block replication before Tat protein expression, resulting in the inhibition of β-galactosidase expression. The PR inhibitor indinavir inhibits virus replication at a step post-Tat expression and has no effect on β-galactosidase expression. PA-457 gives results similar to indinavir, indicating that it blocks virus replication at a point post-Tat expression. All compounds were added at time zero and tested at 5 μg/ml.