Fig. 3.

Binding of MPO-oxidized apoA-I to ABCA1. BHK cells transfected with ABCA1 were incubated for 2 h at 37°C with 1 (A) or 2 (B) µg/ml ¹²⁵I-apoA-I minus (None) or plus 2 (A) or 10 (B) µg/ml unlabeled control apoA-I (Ctrl) or apoA-I treated with reagent HOCl or ONOO⁻ or with MPO and H₂O₂ in the presence of either 100 mM NaCl (MPO-Cl) or 100 μM NaNO₂ (MPO-NO₂). Oxidation reactions were carried out at a 25:1 (A) or 50:1 (B) (mol:mol) ratio of oxidant to apoA-I. Cells were treated with the cross-linker DSP, detergent-solubilized ABCA1 was immunoprecipitated and isolated by reduced SDS PAGE, and ¹²⁵I-apoA-I was visualized by phosphorimaging (A) and quantified (B). Results are representative of five similar experiments. Values in (B) are the mean ± SD of 4–6 incubations from two experiments (*P < 0.001).