Table 3.
Comparison of Fc variants generated by directed mutagenesis to increase FcRn binding.
| Fc variants | Mutations | Ratio variant/parental variant | SD |
|---|---|---|---|
| C6A-69E | P228R/C6A-69 | 1.1 | 0.3 |
| C6A-69 | T307A/N315D/A330V/E382V/N389T/N434Y | 1.0 | 0.2 |
| C6A-69C | P230S/C6A-69 | 0.9 | 0.1 |
| C6A-69D | P228L/C6A-69 | 0.5 | 0.1 |
| C6A-78D | P228R/C6A-78A | 3.3 | 0.8 |
| C6A-78B | P228L/C6A-78A | 1.7 | 0.2 |
| C6A-78F | P228R/P230S/C6A-78A | 1.1 | 0.2 |
| C6A-78C | P230S/C6A-78A | 1.1 | 0.3 |
| C6A-78A | T256N/A378V/N434Y | 1.0 | 0.1 |
| C6A-78E | P228L/P230S/C6A-78A | 0.7 | 0.0 |
| T5A-74D | P228R/T5A-74 | 3.0 | 0.7 |
| T5A-74F | P228R/P230S/T5A-74 | 2.0 | 0.6 |
| T5A-74 | N315D/A330V/N361D/A378V/N434Y | 1.0 | 0.2 |
| T5A-74C | P228L/T5A-74 | 0.9 | 0.2 |
| T5A-74E | P228L/P230S/T5A-74 | 0.8 | 0.2 |
| T5A-74B | P230S/T5A-74 | 0.7 | 0.2 |
| C6A-74D | P228R/C6A-74 | 2.2 | 0.5 |
| C6A-74C | P228L/C6A-74 | 1.3 | 0.3 |
| C6A-74E | P228L/P230S/C6A-74 | 1.0 | 0.3 |
| C6A-74 | V259I/N315D/N434Y | 1.0 | 0.2 |
| C6A-74F | P228R/P230S/C6A-74 | 0.9 | 0.2 |
| C6A-74A | P230S/C6A-74 | 0.7 | 0.1 |
| C6A-60 | P230S/N315D/M428L/N434Y | 1.0 | 0.2 |
| C6A-60D | P228R/C6A-60 | 0.9 | 0.2 |
| C6A-60C | P228L/C6A-60 | 0.6 | 0.2 |
The positions in the hinge domain (P228 and P230) identified by random mutagenesis were combined with our five best variants using directed mutagenesis and resulted in further increased FcRn binding in phage-ELISA assays.