Concentration-dependent effect of TF on uPA-mediated activation of Glu-plasminogen. Glu-plasminogen (5 nmol/L) was incubated with tcuPA (5 nmol/L), the plasmin chromogenic substrate (100 μmol/L), and the indicated concentrations of relipidated TF for 15 minutes under the conditions described in Fig 4 and the absorbance at 405 nm was measured. The data are expressed relative to the absorbance measured in the absence of TF. The mean ± SD of three separate experiments performed in triplicate is shown.