Figure 7. PRO 2000 binds the gp140_CN54 coreceptor binding site and protects against vaginal lavage-mediated degradation.

(A) gp140_CN54 and the control protein BSA were immobilized on a CM5 sensor chip and 100 µM PRO 2000 was flowed over the chip. The mean curve (solid line) ± SD (dashed line) of three independent experiments is shown. (B) Competition of PRO 2000 with mAb-binding (mAbs used at 50% binding concentration) was determined by ELISA using immobilized gp140_CN54; Means of triplicates ± SD are shown. (C) Western blot of gp140_CN54 in human vaginal lavage incubated either alone or in the presence of 100 µM PRO 2000 at 37°C for the indicated periods of time. Uncleaved gp140 shows an apparent mol wt of 160 kDa. (D) Quantification of four independent stability experiments ± SD. *p<0.05.