Fig. 5.

Specific activity of HsARD proteins bound to different metal ions. The assay was performed in argon-saturated 50 mM HEPES pH 7.0, 1 mM MgCl₂ buffer with 0.6 µM E1 enzyme, 500 µM E1 substrate in a total volume of 1 mL. A controlled amount of ARD was added and the depletion of acireductone was monitored spectrophotometrically at 308 nm. The errors are represented as standard deviations of three replicates.