Figure 5. Zinc(II)- and iron(II)-constituted S39E and wild-type HDAC8 catalyzed deacetylation of fluorescently-labeled Fluor de Lys HDAC8 test substrate.
Dependence of the initial rates of deacetylation of the Fluor-de-Lys HDAC8 peptide substrate on substrate concentration catalyzed by A. Zn(II)-constituted S39E HDAC8 (closed blue circles) and Zn(II)-constituted WT HDAC8 (open blue circles) and B. Fe(II)-constituted S39E HDAC8 (closed red circles) and Fe(II)-constituted WT HDAC8 (open red circles). Enzyme concentration was 0.5–1 μM and substrate concentration was 10–1000 μM. The data are a combination of four experiments (Zn(II)-S39E), or one experiment (Zn(II)-WT, Fe(II)-S39E, Fe(II)-WT), and the Michaelis-Menten equation (Equation 1) was fit to the data using global regression analysis (GraphPad Prism).