Table 1. Binding kinetics of Fab fragments with different residues in heavy chain positions 52, 53 and 55 to CMV strain VR1814 gH/gL.
Variant | Sequencea | kon (M−1s−1)b | koff (s−1)b | KD (pM) |
---|---|---|---|---|
MSL-109 | NSDST | 5.2 × 106 | 5.2 × 10−4 | 100 |
D53N/T55R | NSNSR | 1.0 × 107 | 6.0 × 10−5 | < 10c |
Germline (IGHV3–21) | SSSSS | 4.6 × 106 | 2.6 × 10−4 | 57 |
Asp-53 only | SSDSS | 2.9 × 106 | 4.6 × 10−4 | 160 |
Thr-55 only | SSSST | 2.3 × 106 | 7.7 × 10−4 | 330 |
aSequence between heavy chain Kabat positions 52 and 55 shown. The second residue is position 52a. b Binding kinetics measured at 37 °C. c Upper-limit of estimated KD shown due to kon and koff values close to or above the detection limit.