Binding of uPA/suPAR-complex to LM-TK⁻cells. (A) The binding of ¹²⁵I-suPAR to LM-TK⁻ cells was tested in the absence or presence of increasing concentrations of unlabeled Gly158scuPA as indicated. No specific binding of ¹²⁵I-suPAR alone was observed. (B) The binding of ¹²⁵I-Gly158scuPA to LM-TK⁻ cells was tested in the absence or presence of increasing concentrations of unlabeled suPAR (•) or the truncated, domain 1-lacking suPAR (○) as indicated. Data represent mean ± SEM (cpm/well) of triplicate wells. Similar results were observed in five separate experiments.