Further characterization of Tuf-Plasminogen interaction.

<p>(A) Binding of plasminogen (10 μg/ml) to immobilized recombinant Tuf proteins (5 μg/ml) derived from various species was assessed by ELISA. Tuf_Sp was used as a positive control, BSA as a negative control for nonspecific binding. Bound plasminogen was detected using a polyclonal plasminogen antiserum. (B) Binding of plasminogen to immobilized Tuf_Ab and Tuf_Lp occurred in a dose-dependent manner. Tuf proteins (5 μg/ml) were immobilized and incubated with increasing amounts of plasminogen. Binding of plasminogen was analyzed by ELISA using a polyclonal plasminogen antiserum. (C) Role of lysine residues in the Tuf_Ab-plasminogen interaction. Binding of plasminogen (10 μg/ml) to immobilized Tuf_Ab was assayed by ELISA, using a polyclonal plasminogen antiserum, in the presence of increasing concentrations of the lysine analog tranexamic acid. (D) Impact of ionic strength on plasminogen binding to Tuf_Ab. Tuf_Ab was immobilized and incubated with plasminogen (10 μg/ml) and increasing concentrations of NaBr. Plasminogen binding was analyzed by ELISA using a polyclonal plasminogen antiserum. Data represent means and standard deviation of at least three different experiments, each conducted in triplicate. **, p ≤ 0.01 and ***, p ≤ 0.001, one-way ANOVA with Bonferroni post hoc test.