Table 2. Molecular determinants of gB/1G2 binding.
| Sample | ka (× 105 M−1 s−1) | kd (× 10−5 s−1) | KD (nM) | Fold difference from WT (KD) | EC50 (μg ml−1) |
|---|---|---|---|---|---|
| gB mutants | |||||
| ΔNgB-glyco | 3.70 | 6.36 | 0.17 | 1.00 | NA |
| Y280A | 0.07 | 19.50 | 29.30 | 170.35 | NA |
| N281A | 2.18 | 4.57 | 0.21 | 1.22 | NA |
| T283A | 3.10 | 6.99 | 0.23 | 1.31 | NA |
| N284A | 3.20 | 7.66 | 0.24 | 1.41 | NA |
| R285A | —* | — | — | — | NA |
| N286A | 7.24 | 4.89 | 0.07 | 0.39 | NA |
| NRN-AAA† | — | — | — | — | NA |
| F290A | 0.66 | 24.90 | 3.79 | 22.03 | NA |
| E292A | 1.32 | 10.80 | 0.82 | 4.75 | NA |
| N293A/D295A | 2.40 | 8.43 | 0.35 | 2.04 | NA |
| YND-AAA‡ | 0.21 | 39.17 | 18.72 | 108.84 | NA |
| F297A | 0.19 | 26.70 | 13.70 | 79.65 | NA |
| F298A | 2.14 | 5.59 | 0.26 | 1.52 | NA |
| I299A | 1.55 | 9.00 | 0.58 | 3.37 | NA |
| F298A/I299A | — | — | — | — | NA |
| 1G2 | |||||
| WT | 2.95 | 3.75 | 0.13 | 1.00 | 0.10 |
| 1G2 heavy chain | |||||
| R31S | 2.73 | 6.07 | 0.22 | 1.76 | 0.05 |
| S32A | 3.96 | 1.06 | 0.03 | 0.21 | 0.09 |
| N102A | 3.06 | 52.60 | 1.71 | 13.46 | 0.67 |
| Y103A | 3.25 | 76.60 | 2.36 | 18.58 | 0.31 |
| F104A | 2.94 | 45.00 | 1.53 | 12.05 | 0.20 |
| Y103A/F104A§ | — | — | — | — | 6.79 |
| Y109A | 3.24 | 7.67 | 0.24 | 1.87 | 0.10 |
| 1G2 light chain | |||||
| Y50A | 3.57 | 11.80 | 0.33 | 2.60 | 0.13 |
| R51A | 3.27 | 5.11 | 0.16 | 1.23 | 0.16 |
NA, not applicable.
Surface plasmon resonance data for various ΔNgB-glyco and 1G2 containing point mutations of residues located at the complex interface. Single cycle kinetics was performed on each pair. Further details are included in Supplementary Table 3. The neutralization potential of 1G2 and its mutants was assessed on ARPE-19 epithelial cells, with EC50 values reported here (far right column).
*=no measurable binding detected.
†NRN-AAA=N284A/R285A/N286A.
‡YND-AAA=Y280A/N293A/D295A.
§=very weak binding.