FIG. 2.

GRL-216 and GRL-286 potently block the dimerization of HIV-1 protease. To examine whether GRL-216 and GRL-286 inhibited HIV-1 protease dimerization, the FRET-based HIV-1 expression system was employed (23). COS7 cells were transfected with pHIV-PR_WT^CFP and pHIV-PR_WT^YFP and exposed to various concentrations of either of the drugs, and the CFP^A/B ratios (y axis) were determined at the end of a 72-h culture. All average CFP^A/B ratios were less than 1.0 in the presence of >0.1 μM GRL-216 and GRL-286, indicating that both compounds effectively blocked HIV-1 protease dimerization.