Competitive binding of CS-6253 peptide to ABCA1 cells expressing ABCA1.

<p>BHK-ABCA1 cells were plated in 24-well plates and stimulated for 20 h. Cells were then incubated with 2 μg/ml of ¹²⁵I-apo A-I for 2 h at 37°C with increasing molar concentrations relative to apo A-I of either CS-6253 peptide, ATI-5261, human apo E, and unlabelled apo A-I (0, 0.0035, 0.017, 0.035, 0.071, 0.17, 0.35, 1.79 μM). Cells were then washed rapidly three times with ice-cold PBS/BSA and then PBS alone. ¹²⁵I-apo A-I cell associated was determined as described under “Experimental Procedures.” The values shown represent the mean ± S.D from triplicate wells. The 100% of control value measured in the absence of competitors was 0.21 ng of apo A-I /μg cell protein. Values of IC₅₀ shown were determined using the Graph Pad Prism 6 software.