Figure 1.

Inactivation of the recombinant and human PON1, and PON1-HDL complexes in the presence of calcium chelator (A) or in buffer (B). Data represents mean ± SD of at least 3 independent experiments. A. Inactivation kinetics of rePON1, rePON1-HDL, huPON1, and huPON1-HDL (huHDL) by EDTA (4 mM) and β-mercaptoethanol (8 mM) at 37°C. Residual activity at various time points was determined by initial rates of phenyl acetate hydrolysis and plotted as percent of the activity at time zero. Data were fitted to a single exponential for rePON1-HDL, and to double-exponentials for the remaining samples [35]. B. Inactivation of rePON1, rePON1-HDL, huPON1, and huPON1-HDL (huHDL), in PBS buffer with 1 mM CaCl₂. Residual PON1 activity after 24 hrs incubation at 37°C is presented as percentage of the initial activity.