FABP3 and FABP8 bind and transfer cholesterol in vitro. (A) Binding of ³H-cholesterol to the indicated FABP proteins. Equal amounts of proteins were used in the reaction. CPM measured for ³H-cholesterol bound to WT FABP7 is defined as 1 and used as the reference for comparison. Data are presented as mean ± SEM (from three independent experiments). Student’s unpaired two-tailed t test with Welch’s correction. (B) Binding of ³H-oleic acid to the indicated FABP proteins. Equal amounts of proteins were used in the reaction. CPM measured for ³H-oleic acid bound to WT FABP7 is defined as 1 and used as the reference for comparison. Data are presented as mean ± SEM (from three independent experiments). Student’s unpaired two-tailed t test with Welch’s correction. (C and D) Binding of ³H-cholesterol to FABP3 (C) and FABP8 (D) in the presence of increasing concentrations of oleic acid. CPM measured for ³H-cholesterol bound to FABP3 (C) and FABP8 (D) in the absence of oleic acid is defined as 1 and used as the reference for comparison. Data are presented as mean ± SEM (from three independent experiments). Student’s unpaired two-tailed t test with Welch’s correction. (E and F) Comparison of the effects of indicated proteins on DHE transfer. Arrow indicates when proteins were added. Initial transport rates were quantified in F. Data are presented as mean ± SEM (from three independent experiments). Student’s unpaired two-tailed t test. Compared with initial transport rates of DHE by FABP7 protein.