Table I.

Binding rate constants of anti-HIV-1 gp41 membrane proximal and anti-cardiolipin mAbsa

mAb/AgkakdKd
×103 M−1 s−1×10−3 s−1nM
4E10 mAb/4E10 peptide63 ± 1.11.2 ± 0.120.2 ± 3.3
4E10 Fab/4E10 peptide40 ± 13.06.2 ± 2.4255 ± 19.2
2F5 mAb/2F5 peptide633 ± 16.80.2 ± 0.010.27 ± 0.2
2F5 Fab/2F5 peptide287 ± 432.6 ± 0.89.0 ± 2.1
13H11 mAb/2F5 peptide488 ± 32.46.6 ± 1.612.4 ± 0.4
4E10 mAb/Con S gp140108 ± 7.11.7 ± 0.3160 ± 38.0
2F5 mAb/ConS gp140NA*NA*>1000
IS6 mAb/Con S gp1405.0 ± 1.93.0 ± 0.22407 ± 86
2F5 mAb/JRFL gp1403.6 ± 0.740.54 ± 0.03164 ± 34.3
4E10 mAb/JRFL gp1401.8 ± 0.21.95 ± 0.171090 ± 15.5
4E10 mAb/cardiolipinNANA37
2F5 mAb/cardiolipinNANA350
IS4 mAb/cardiolipinNANA12.0
IS6 mAb/cardiolipinNANA∼1000
2F5 peptide-lipid, encounter5100.15
2F5 peptide-lipid, docking0.05 (s−1)3.31.8
4E10 peptide-lipid, encounter1900.15
4E10 peptide-lipid, docking0.02 (s−1)1.521.5
  • a NA: Due to biphasic nature of binding of mAbs to cardiolipin, Kd values from equilibrium-binding analyses are given. NA*: due to the low level of binding, reliable rate constants could not be measured.

  • For mAb binding to peptide-lipid conjugates, rate constants for the encounter and docking steps were determined by curve fitting to the conformational change model. Mean and SE data are provided for binding studies in which at least three independent studies were performed.