TABLE 2.

Binding kinetics of interactions between anti-HIV antibody fragments to SF162-derived epitope peptidesa

EpitopeKD (nM)SF162 gp140 monomer bindingSF162 gp140 trimer binding
kOFF/kON (nM)kON (M−1 s−1)kOFF (s−1)kOFF/kON (nM)kON (M−1 s−1)kOFF (s−1)
Fv4E10wt12 (1)108 (1)[2.50 (2)] E4[2.70 (2)] E-398 (1)[2.70 (2)] E4[2.60 (2)] E-3
Fv4E10[W(H100)A]14 (1)106 (2)[2.40 (2)] E4[2.50 (2)] E-3119 (2)[2.10 (2)] E4[2.50 (2)] E-3
Fv4E10[G(L50)E]16 (1)136 (2)[2.00 (2)] E4[2.70 (2)] E-3114 (2)[2.00 (2)] E4[2.30 (2)] E-3
Fab4E1010 (1)130 (2)[1.70 (2)] E4[2.20 (2)] E-3135 (2)[2.00 (2)] E4[2.70 (1)] E-3
IgG447199 (6)
Fab447 (state 1)92 (2)*[3.40 (5)] E5[4.90 (9)] E-293 (1)*[2.60 (2)] E5[3.60 (3)] E-2
Fab447 (state 2)[2.06 (2)] E-3[3.45 (4)] E-3[2.66 (7)] E-3[5.8 (1)] E-3
  • a Values are means, with standard errors in parentheses. Epitope peptides were the 4E10 or 447-52D sequence or gp140 monomers or trimers as measured by SPR at 25°C. *, equilibrium constants were determined using BIAevaluation 2.0 software (Biacore AB) with a two-state fitting model; state 2 on-rates have units of s−1.