Figure 2.

Characterization of SMTP-7 in vitro. (A) Effects on plasminogen activation by t-PA and u-PA. Plasminogen activation was assayed using t-PA or u-PA in the presence of the indicated concentrations of SMTP-7. (B) Kinetic measurements of u-PA-catalyzed plasminogen activation in the presence of SMTP-7 (100 μM). Parameters shown were obtained from triplicate determinations. (C) Effect on plasminogen conversion to plasmin. u-PA-catalyzed ¹²⁵I-plasminogen conversion to plasmin was assayed in the presence or absence of SMTP-7 (100 μM). Positions of plasminogen (Plg) and A- and B-chains of plasmin are shown. (D) Effects on amidolytic activities of plasmin, t-PA, and u-PA. Activity of each enzyme was determined using a fluorogenic substrate in the presence of the indicated concentrations of SMTP-7. (E) Size-exclusion chromatography. Alexa 488-labeled plasminogen was eluted in the absence or presence of SMTP-7 (120 μM). **, P < 0.05 by Student's t-test. Error bars in panels A, B, D, and E represent SD from triplicate determinations.