Modulation of C1-Inhibitor and Plasma Kallikrein Activities by Type IV Collagen

Figure 5

The time course of inactivation of kallikrein, factor XIIa, and β-factor XIIa by type IV collagen. Kallikrein was incubated with 20 μg/mL collagen (◆) or 100 μg/mL collagen (■), factor XIIa was incubated with 20 μg/mL collagen (▲) or 100 μg/collagen (×), and β-factor XIIa was incubated with 20 μg/mL collagen (*) or 5 μg/mL collagen (•). At the indicated times, a sample was assayed for residual activity with S-2302. The activity is presented as the percentage of the original activity prior to incubation. In the absence of collagen, there was no loss of activity during the same time course.