Figure 3. GTPase activity of human LRRK2 Roc-COR-kinase fragments.

Left: Inorganic phosphate release of 100 nM LRRK2 protein incubated with 500 μM γ³²P-GTP during the indicated time. The slopes of the linear fits of phosphate release at different time-points yield the reaction rates (v). Right: The reaction rates (v) of wild-type and the R1441C PD-mutant of human LRRK2 Roc-COR-kinase proteins are plotted against substrate (GTP) concentration. The error bars show the standard error of the reaction rate calculated from at least three measurements. k_cat and K_m values are calculated by fitting the data with the Michaelis–Menten equation using GraFit (Erithacus Software).