Effect of lipid competitors on the binding of NO₂-LDL to CD36-transfected cells. [¹²⁵I]LDL was modified as described for the complete system in Figure 2a. [¹²⁵I]-NO₂LDL (5 μg/mL) was then incubated with CD36-expressing 293 cells for 3 hours at 4°C in the presence of (a) 20 μg lipid/mL or (b) the indicated concentrations (μg lipid/mL) of competitors. PAPC, PAPC(SnCl₂), PLPC, and POPC unilamellar vesicles were oxidized for 8 hours at 37°C as described for the complete system in Figure 2 in the presence (+NO₂^–, filled symbols) or absence (–NO₂^–, open symbols) of NO₂^–. Where indicated, BSA (0.2 mg protein/mL final concentration) was also included during liposome preparation as described in Methods (hatched bars). PAPC (SnCl₂), hydroperoxide-free PAPC generated by reduction of PAPC with SnCl₂, and then reisolation of PAPC under argon atmosphere before use were used as described in Methods. Data represent the mean ± SD of triplicate determinations (a) or means of triplicate determinations (b) of a representative experiment performed 3 times. ^AP < 0.001 for comparison versus control (no competitor).