TABLE 1.
Effect of XOMA 052 on affinities of IL-1β interactions
Measurements by SPR are consistent with KinExA and demonstrate that XOMA 052 reduces the affinity of IL-1β binding to IL-1 sRI and sRAcP, but not IL-1 sRII. Affinities are the average of multiple (n) independent experiments. Methods for SPR experiments are described in the supplemental data. NA, not applicable.
| Interaction by SPR | Immobilized on SPR chip | Injected | No Antibody | +XOMA 052 | n |
|---|---|---|---|---|---|
| nm | nm | ||||
| IL-1β + sRI ↔ IL-1β·sRI | sRI | IL-1β ± XOMA 052 | 0.7 ± 0.1 | 6.1 ± 0.2 | 5 |
| sRI·biotin | IL-1β ± XOMA 052 | 0.5 ± 0.2 | 4.3 ± 0.3 | 3 | |
| sRI·Fc chimera | IL-1β | 0.5 ± 0.2 | NA | 3 | |
| XOMA 052·biotin + IL-1β | sRI | NA | 10 ± 4 | 5 | |
| IL-1β + sRII ↔ IL-1β·sRII | sRII | IL-1β ± XOMA 052 | 7 ± 2 | 8 ± 3 | 5 |
| sRII·biotin | IL-1β ± XOMA 052 | 7.3 ± 0.6 | 6 ± 1 | 5 | |
| XOMA 052·biotin + IL-1β | sRII | NA | 2 ± 1 | 3 | |
| IL-1β·sRI + sRAcP-Fc ↔ IL-1β·sRI·sRAcP-Fc | sRAcP·Fc·biotin | sRI/IL-1β ± XOMA 052 | 25 ± 4 | 70 ± 20 | 3 |
| IL-1β·sRII + sRAcP-Fc ↔ IL1β·sRII·sRAcP-Fc | sRII·biotin + IL-1β ± XOMA 052 | sRAcP·Fc | 28 ± 12 | 22 ± 6 | 2 |