Glycation Sensitivity of Apolipoprotein A-I

The glycation sensitivity was compared by incubating the purified lipid-free apoA-I (final 1 mg/mL) with 250 mM D-fructose (Sigma # F2793) in 200 mM potassium phosphate/0.02% sodium azide buffer (pH 7.4), as reported elsewhere [21 (link),37 (link)]. ApoA-I was incubated for up to 48 h in an atmosphere containing 5% CO₂ at 37 °C. The extent of the advanced glycation reactions was determined by reading the fluorescence intensities at 370 nm (excitation) and 440 nm (emission), as described previously [56 (link)], using an FL6500 spectrofluorometer (Perkin-Elmer, Norwalk, CT, USA) with Spectrum FL software version 1.2.0.583 (Perkin–Elmer) and a 1 cm path-length Suprasil quartz cuvette (Fisher Scientific, Pittsburgh, PA, USA).