Figure 3

a, SDS-PAGE and fibrin autography of whole vessel extracts of a representative pair of Pa and Ao. The Biorad Kaleidoscope Prestained Standards 61–0234 were used for sizing of proteins. Recombinant t-PA (50 ng) was loaded in lane rt-PA. Ao protein extracts (5 μg) (lane Ao) and Pa protein extracts (5 μg) (lane Pa) were loaded. Photographs were taken after prolonged exposure at 37° C to favor visualization of t-PA–PAI-1 complexes. b, Western blot experiment using anti-t-PA to visualize 50 ng of recombinant human t-PA, 30 μg of Ao protein extract (lane Ao), and 30 μg of Pa protein extract (lane Pa). The additional lower bands are thought to represent cleaved t-PA. Under the given conditions, t-PA–PAI-1 complexes are not visualized. Negative controls in the absence of primary antibody did not show any bands. c, Western blot experiment using anti–urokinase-type PA to visualize 30,000 IU of human urokinase-type PA, 30 μg of Ao protein extract (lane Ao), and 30 μg of Pa protein extract (lane Pa).