Fig. 4.

Binding and competition assays performed with the hybrid β-lactamase containing CD22 residues V234–G435, referred to as the bifunctional hybrid protein (BHP). (A) Binding assay performed on 200 ng of coated mAb anti-IL6 or mAb 8015 with 130 ng of BHP. (B) Competition assays performed on 200 ng of coated mAb 8015 with 1.3 µg of BHP supplemented with 1.3 µg (1/1), 2.6 µg (1/2) or 7.5 µg (1/5) of free mAb anti-IL6 or free mAb 8015. (C) Competition assays performed on 100 ng of coated mAb 8015 and mAb epratuzumab with 1.3 µg of BHP supplemented with 1.3 µg (1/1), 2.6 µg (1/2) or 7.5 µg (1/5) of free mAb 8015. Nitrocefin (100 µM) was used as reporter substrate.