Figure 5.

Ixonnexin does not bind to urokinase. (A) Ixonnexin was immobilized in 96-well plates as indicated and incubated with Lys-plasminogen. Reactions were initiated with urokinase (0.1 nM) or t-PA (2.5 nM), and plasmin formation was detected with chromogenic substrate S2251 (250 μM). SPR experiments: Ixonnexin was immobilized in a sensor chip and (B) urokinase (15–250 nM) or (C) plasmin (15–250 nM) were tested as analytes. Dissociation of the complexes was monitored for 600 seconds, and a two-state reaction binding model was employed for urokinase and Langmuir equation (1:1) for plasmin. Representative sensorgrams are shown in black, and fitting of the data points is depicted in red. Representative experiments are shown.