FIG. 4.
Biochemical characterization of PA-457-resistant mutants in an in vitro assembly system. [35S]Met-labeled assembled Gag was used as substrate for proteolytic processing by 3 h of incubation with purified PR in the presence or absence of PA-457 at the indicated concentrations. (A) Portions of gels from representative experiments showing CA-SP1 and CA. The concentration of PA-457 is given at tops of gel lanes (0.6 μg/ml ∼ 1 μM; 6 μg/ml ∼ 10 μM). (B) Quantitative representation of the gel data from panel A normalized to the maximum amount of processing as seen in the no-drug control. (C) Extent of cleavage achieved under standard reaction conditions in the absence of drug, presented as percentage of CA-SP1 relative to total CA-SP1 plus CA. For panels B and C, error bars indicate the standard deviations for six replicate experiments. Note that the data for SP1-A1V were reported in a previous study (38) and are recapitulated here for comparison.