FIGURE 6.

SK-plasmin and SUPA-plasmin resistance to α₂-antiplasmin inhibition. Plasmin (0.25 μm) was mixed with SK (0.25 μm) or varying concentrations of SUPA (0.25 or 2.5 μm) in HEPES/NaOAc buffer and incubated on ice for 20 min, followed by the addition of 0.25 μm α₂-antiplasmin (α2AP) and incubation for an additional 10 min. Samples were analyzed by SDS-PAGE under nonreducing conditions using Western blotting. The formation of the plasmin-α₂-antiplasmin complex was detected by mouse anti-human α₂-antiplasmin monoclonal antibody at the appropriate molecular size as indicated. First lane, plasmin alone; second lane, α₂-antiplasmin alone; third lane, plasmin and α₂-antiplasmin; fourth lane, plasmin, 0.25 μm SK, and α₂-antiplasmin; fifth and sixth lanes, plasmin and 0.25 or 2.5 μm SUPA (respectively) mixed with α₂-antiplasmin.