FIG. 2.

Association of Vif with virions purified by Optiprep gradient velocity centrifugation. Wild-type HIV-1 NL4-3 (top set of panels) and GagΔNC NL4-3 (middle set) produced in 293T cells or HIV-1 KS283 produced in MT-2 (bottom set) were resolved by velocity Optiprep gradient centrifugation. The gradient fractions were collected from the bottom (left, starting with number 1), and pelleted virions from each fraction were resolved on SDS-PAGE. In the HIV KS283 gradient, virions were also collected from the bottom of the centrifugation tube (B). Vif was detected by immunoblotting with anti-Vif rabbit antiserum (lower panel in each set), and Gag was detected by reprobing of stripped membranes with anti-CA monoclonal antibody (top panel in each set).