Impact of Gln, Glu, Lys and Arg on calculated pI.
| Modification | Calculated pI | Change in pI relative to parental antibody |
|---|---|---|
| Anti TNF | 8.72 | — |
| Anti TNF + 4 Gln | 8.72 | 0 |
| Anti TNF + 10 Gln | 8.72 | 0 |
| Anti TNF + 4 Glu | 7.96 | −0.8 |
| Anti TNF + 10 Glu | 7.12 | −1.6 |
| Anti TNF + 4 Lys | 9.10 | 0.4 |
| Anti TNF + 10 Lys | 9.40 | 0.7 |
| Anti TNF + 4 Arg | 9.12 | 0.4 |
| Anti TNF + 10 Arg | 9.42 | 0.7 |