Figure 2.

Env and GFP-TM1 incorporation levels correlate with immature particle stiffness. Different amounts of WT Env (A) or GFP-TM1 (B) were incorporated into immature HIV-1, and the particle stiffness of these viruses was measured using AFM. At least 16 particles were measured for each stiffness value, except the two highest GFP-TM1 points, which produced low particle yields (4 and 6 particles measured, respectively). Viral particle stiffness is plotted against Env or GFP-TM1 incorporation levels normalized to virus with highest level of incorporation (open circles, linear fit shown). The GFP-TM1 titration series was analyzed together with immature WT (filled circle). Error bars show SEM.