TABLE 2.
Binding kinetics of interactions between anti-HIV antibody fragments to SF162-derived epitope peptidesa
| Epitope | KD (nM) | SF162 gp140 monomer binding |
SF162 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) | ||
| Fv4E10wt | 12 (1) | 108 (1) | [2.50 (2)] E4 | [2.70 (2)] E-3 | 98 (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-3 | 119 (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-3 | 114 (2) | [2.00 (2)] E4 | [2.30 (2)] E-3 |
| Fab4E10 | 10 (1) | 130 (2) | [1.70 (2)] E4 | [2.20 (2)] E-3 | 135 (2) | [2.00 (2)] E4 | [2.70 (1)] E-3 |
| IgG447 | 199 (6) | ||||||
| Fab447 (state 1) | 92 (2)* | [3.40 (5)] E5 | [4.90 (9)] E-2 | 93 (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.