Table 3. Binding affinities of anti-CD20 IgG1 rituximab variants to shFcγRs.
| Wild-type | Y296W | Y296A | Y296K | |||||
|---|---|---|---|---|---|---|---|---|
| Average K
D (×10−8 M) (K D wild = 1) |
Fu(+) | Fu(-) | Fu(+) | Fu(-) | Fu(+) | Fu(-) | Fu(+) | Fu(-) |
| FcγRIIIa(V) | 25.7 ± 2.2 (1) | 7.61 ± 0.44 (1) | 13.3 ± 1.8 (1.93) | 5.23 ± 0.17 (1.46) | 54.9 ± 2.0 (0.47) | 22.9 ± 0.59 (0.33) | 87.6 ± 9.9 (0.29) | 46.8 ± 1.6 (0.16) |
| FcγRIIIa(F) | 165 ± 3.7 (1) | 49.9 ± 1.2 (1) | 74.9 ± 0.96 (2.2) | 36.6 ± 0.95 (1.36) | 411 ± 17 (0.4) | 146 ± 3.6 (0.34) | 704 ± 36 (0.23) | 395 ± 23 (0.13) |
| FcγRIIIb | 187 ± 6.7 (1) | 20.2 ± 0.39 (1) | 157 ± 13 (1.19) | 17.9 ± 0.41 (1.13) | 222 ± 11 (0.84) | 198 ± 3.6 (0.1) | 305 ± 14 (0.61) | 364 ± 19 (0.06) |
| FcγRIIa | 174± 3.4 (1) | 116 ± 2.0 (1) | 81.5 ± 0.98 (2.13) | 69.2 ± 2.3 (1.68) | 126 ± 1.2 (1.39) | 151 ± 6.87 (0.77) | 113 ± 1.2 (1.54) | 153 ± 5.9 (0.76) |
| FcγRI | 11.2 ± 0.81 (1) | 10.4 ± 0.34 (1) | 9.67 ± 0.34 (1.16) | 8.1 ± 0.66 (1.28) | 10.6 ± 0.93 (1.05) | 10.1 ± 0.74 (1.03) | 10.6 ± 0.78 (1.06) | 10.5 ± 0.84 (0.99) |
The values in parentheses indicated fold changes relative to wild-type. The mean K D value (n = 3) is indicated on the Y axis; bars ± standard deviations (SDs). Fu(+): fucosylated; Fu(-): nonfucosylated.