Sensorgrams for interactions between targeted factors (kallikrein, FXIa, FXIIa, and plasmin) and immobilized Ir-CPI measured by surface plasmon resonance. Ir-CPI was immobilized on the surface of a CM5 sensor chip at a level of 200 RU. Factors (from 5 to 300 nM) were injected at a flow rate of 70 µl/min in HBS buffer, and association was monitored for 84 s. After return to buffer flow, dissociation was monitored for 150 s. The sensor chip surface was regenerated by a pulse injection of 25 mM NaOH after each experiment. For each interaction, one representative result from three independent determinations is shown.