FIGURE 2.

Aggregated LDL is specifically recognized by LRP1 cluster II. A, schematic representation of the fluorometric assay developed to detect AgLDL binding to LRP1 minireceptors. Briefly, recombinantly expressed clusters II–IV or the CR4/CR8 tandem were immobilized on the wells of a microplate using an anti-c-Myc capture antibody and then incubated with various amounts of fluorescent labeled native or aggregated LDL. Supernatants from CHO-K1 cells transfected with the empty vector were used as background control. (See “Experimental Procedures” for details). B, affinity of generated LRP1 fragments for DiI-labeled lipoproteins. Measured fluorescent intensities are given as mean ± S.D. (error bars) of four different experiments performed in duplicate. *, p < 0.05 versus AgLDL binding to background.