Figure 3.

Mutations at the NTD-CTD intersubunit interface impair HIV-1 infectivity and alter capsid stability. (A) Production of viral particles as measured by RT activity. (B) Immunoblot analysis of viral lysates. Virions were collected from transfected 293T cells, pelleted, and analyzed by SDS-PAGE and immunoblotting with a CA specific polyclonal antibody. (C) Single-cycle infectivity of the mutant virions. Virion stocks were titrated on TZM-bl reporter cells and the extent of infection was determined by quantification of luciferase reporter activity in cell lysates. Values were normalized by the corresponding values of reverse transcriptase activity in the inocula. Results shown are the mean values of three independent experiments, with error bars representing one SD. (D) Quantification of core-associated CA. Cores were purified from the concentrated virions, and the levels of the core-associated CA were determined as a percentage of the total virion-associated CA. The values shown are the means of three independent experiments; error bars represent one SD.