Fig 5. Probing exposure of the three gp41 C-HR domains.
(A) 5HLAVA sensitivity of Ww (black), Wm (red), Mw (green) and Mm (blue) viruses where mutant Env protomers contained the N656D substitution. Viral samples were produced from cells expressing equal levels of Env A and Env B protomers. (B) IC50 values for 5HLAVA (dark gray) and 5HWT (light gray) against HIV-1 produced from cells expressing equal levels of Env A and Env B protomers. 5HLAVA is affinity-dependent while 5HWT is kinetically restricted. (C and D) IC50 values for 5HLAVA (C) and 5HWT (D) against HIV-1 produced from cells expressing Env A and Env B protomers at the indicated ratios. IC50 values (B, C and D) were obtained as described in Fig 4. Data points represent the means ± SEM from five independent experiments. The target cells were U87.CD4.CXCR4.