Fig. 4.

Enzyme kinetics of AgUricases. The activities of wild-type (circle), K12C–E286C (square), and S296C–C302S (triangle) mutant AgUricase were measured by substrate (UA) depletion assays. The rate (specific activity) of UA oxidation was calculated based on the linear decrease in absorbance at 292 nm. The data were fit to the Michaelis–Menten equation by GraphPad Prism 7 to determine the k_cat and K_m values. The data are presented as the mean ± standard error of the mean (SEM) of at least three independent experiments