Figure 6.

ABCA1 CEC (A), HDL particle size distribution (B), free cholesterol (C), and total cholesterol (D) content of control and LCAT-deficient plasma incubated with LCAT. Control plasma (n=3) and LCAT-deficient plasma (n=3) were incubated with and without recombinant human LCAT (rLCAT+ and rLCAT-; 50 μg/mL) for 1 h at 37 ^⁰C. The LCAT reaction was stopped with 2 mM of DTNB and cooling on ice. Control studies demonstrated that DTNB did not alter the CEC of plasma. DTNB was omitted from plasma used to quantify cholesterol levels because it interfered with the enzymatic assay. ABCA1 CEC of plasma was quantified using [³H]cholesterol-labeled baby hamster kidney cells as described in the legend to Figure 5. P values, ratio t test. ABCA1 indicates ATP-binding cassette transporter A1; CEC, cholesterol efflux capacity; HDL, high-density lipoprotein; HDL-P, HDL particle concentration determined by calibrated ion mobility analysis; LCAT, lecithin-cholesterol acyltransferase; S-HDL, small HDL; and XS-HDL, extra-small HDL.