Figure 4.

Second-site suppressor mutations do not restore capsid stability in vitro. (A and B) Concentrated virions were subjected to ultracentrifugation through a detergent layer into a sucrose density gradient. Yields of cores were calculated as the percentage of the total CA that was detected in the peak fractions of cores. Results shown are the mean values of three independent experiments, with error bars representing one standard deviation. (C) Disassembly of purified HIV-1 cores in vitro. Diluted HIV-1 cores were incubated at 37°C for the indicated times, followed by separation of free and core-associated CA by ultracentrifugation. Supernatants and pellets were analyzed by p24 ELISA. The extent of disassembly was determined as the percentage of the total CA protein in the reaction detected in the supernatant. Results shown are the average values of two independent experiments with duplicate determinations in each experiment. Error bars represent the spread of values obtained in the two experiments.