FIGURE 7.

FLVCR directly interacts with hemopexin. A, the FLVCR peptide-GST fusion protein preincubated with heme (stippled bars) or without heme (solid bars) was coated onto a 96-well microplate in a 1:2 series dilution as indicated. Hemopexin (290 nm) binding to the FLVCR peptide-GST fusion protein was detected by rabbit anti-hemopexin antibody and horseradish peroxidase-labeled goat anti-rabbit antibody, followed by incubation with 3,3′,5,5′-tetramethylbenzidine chromogenic solution. Hemopexin bound to the FLVCR peptide-GST fusion protein in a dose-dependent manner. B, preincubation of hemopexin with the FLVCR peptide (gray bars) or heme (stippled bars), in comparison with the untreated control (black bars), decreased its ability to bind to the FLVCR peptide-GST fusion protein. Data from A and B together show that apohemopexin bound to FLVCR more avidly than heme-hemopexin.