Figure 4. Kinetics of HK cleavage.

HK (200 µg/ml) was incubated with (A) kallikrein (0.5 µg/ml), (B) rMASP-1 (50 µg/ml), or (C) rMASP-2 (30 µg/ml) in HBS buffer (see Methods) at 37°C. Samples were taken periodically (time in minutes indicated), and 15 µl aliquots were run on SDS-PA gels under reducing conditions. The kinetic constants, determined by densitometry of the HK band followed by non-linear regression analysis, are found in Table 1.