FIGURE 7.

Effect of clusters II and IV on LRP1-mediated internalization of BDD-fVIII (A) and tPA·PAI-1 (B) by WI-38 fibroblasts. WI-38 fibroblasts were seeded in 12-well tissue culture dishes (1 × 10⁵ cells/well) and incubated with 20 nm ¹²⁵I-BDD-fVIII (A) or 10 nm ¹²⁵I-tPA·PAI-1 (B) for 4 h at 37 °C in the presence or absence of LRP1 cluster II or IV (500 nm). Following incubation, the amount of radiolabeled ligand internalized was determined, and the data were normalized to the amount of fVIII internalized in the absence of competitors. The results represent the mean of three independent experiments. Error bars represent S.E. (*, p ≤ 0.002, one-way analysis of variance with Tukey's multiple comparison post-test).