FIG. 4.

Size exclusion chromatography of HIV-1 proteins. Elution profiles of wild-type (C) and mutant proteins L241A and L242A (A and B, respectively). The retention time in minutes is indicated on the x axis, and the A₂₈₀ in arbitrary units (AU) is indicated on the y axis. Molecular mass markers for size exclusion chromatography are indicated by open arrows above panel A: a, aldolase, 158 kDa, retention time, 40 min; b, bovine serum albumin, 67 kDa, retention time, 54 min; c, chymotrypsin, 25 kDa, retention time, 66 min. The retention time of the IN tetramer is 47 min, and that of the IN dimer is 59 min (filled arrows). (D) IN samples analyzed by SDS–12.5% PAGE at various retention times. Molecular mass standards are indicated on the left in kilodaltons.