FIG. 6.

Assembly kinetics of purified HIV-1 CA proteins. (A) His-tagged wild-type or mutant HIV-1 p24 CA proteins were expressed in bacteria and purified by Ni-NTA column chromatography. Portions (20 μg) of each purified CA protein were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Coomassie blue staining. (B) Each CA protein, at a concentration of 44 μM, was assembled in 2.5 M NaCl. The optical density at 340 nm was monitored every 10 s. (C) The initial rate of assembly for each CA protein was estimated by fitting the increase in optical density at early times (0 to 120 s) to a straight line, using a least-squares approximation. Error bars represent the standard deviations of three independent estimations. wt, wild type.