Parameters used to calculate .

The rate constants are from the SPR experiments in Figure 3 of Alam et al. [4]. In these experiments Fab or mAb binds from solution to peptide-liposome conjugates. The best fit is obtained with a two-step conformational change model. The forward and reverse rate constants and characterize the encounter complex step. The forward and reverse rate constants and characterize the docking step. When , the rate at which triplets of gp41 are rendered nonfunctional, is much faster than , no longer enters the calculation. The parameter is calculated from Eq. (10).