Double reciprocal plot of the rate of reduction of glyceraldehyde by wild-type AKR1B10. Lineweaver–Burk plots of rate of reduction of DL-glyceraldehyde in the presence of various concentrations of (A) ciprofibrate (● — 0 μM; ○ — 10 μM; ▲ — 20 μM; Δ — 50 μM; ■ — 100 μM; □ — 200 μM), (B) EBPC (● — 0 μM; ○ — 0.5 μM; ▲ — 1 μM; Δ — 2 μM; ■ — 5 μM; □ — 10 μM; ♦ — 20 μM), (C) fenofibrate (● — 0 μM; ○ — 1 μM; ▲ — 2 μM; Δ — 5 μM; ■ — 10 μM; □ —20 μM), (D) fenofibric acid (● — 0 μM; ○ — 10 μM; ▲ — 20 μM; Δ — 50 μM; ■ — 100 μM; □ — 200 μM), (E) sorbinil (● — 0 μM; ○ — 5 μM; ▲ — 10 μM; Δ — 20 μM; ■ — 50 μM; □ — 100 μM), (F) Wy 14,643 (● — 0 μM; ○ — 5 μM; ▲ — 10 μM; Δ — 20 μM; ■ — 40 μM; □ — 50 μM) and (G) zopolrestat (● — 0 μM; ○ — 1 μM; ▲ — 2 μM; Δ — 5 μM; ■ — 10 μM; □ — 20 μM). Each individual rate measurement was evaluated in triplicate.unit of AKR1B0 enzyme activity is defined as μmoles of NADPH oxidized/min..