FIGURE 7.

Degradation of C5 by plasmin bound to BBA70. Recombinant BBA70, ErpP, BBA66, and BSA (20 μg/ml) were immobilized onto microtiter plates and incubated with 20 μg/ml plasminogen. After washing, a reaction mixture containing 0.16 μg/ml activator uPA and 5 μg/ml C5 was added. Microtiter plates were incubated at 37 °C, and aliquots were taken at various time intervals. The mixtures were then separated via SDS-PAGE, and C5 as well as its degradation products were detected with a polyclonal goat anti-C5 antiserum and a corresponding anti-goat HRP-conjugated secondary antibody. Representative results of two separate experiments are shown. Arrows, α- and β-chain of C5; arrowhead, degradation product of C5 α-chain of ∼87 kDa. A, a visible degradation product appears after 24 h of incubation for plasmin bound to both BBA70 (left) and ErpP (right). B, no degradation products could be observed for BBA66 (left) or BSA (right). C5, purified human C5. Negative controls include the addition of 50 mm tranexamic acid (+T) as well as omission of plasminogen (−Plg).