Fig. 1: Kinetic analysis of TbGMPR in the presence of purine nucleotides.
a, b The initial velocities of TbGMPR in the presence of GTP (a) or ATP (b) at a fixed concentration of GMP and NADPH. Each trinucleotide was used as a premix with (solid bars) or without (shaded bars) equivalent amount of magnesium ions. c The initial velocities of TbGMPR were plotted against the concentrations of GMP in the absence (open circles) or presence of 1 mM GTP (blue) or ATP (red) at a fixed concentration of NADPH. Data were fitted to the Hill equation, as described in the “Methods”. d The catalytic efficiency (kcat/K0.5) of TbGMPR in the presence of various concentrations of GTP (blue) or ATP (red) ligand alone. e The initial velocities of TbGMPR in the absence (red) or presence of 1 (orange), 10 (green), 100 µM (blue), or 1 mM GTP (magenta) under fixed concentration of ATP at 1 mM. Note that the kinetics with GTP at 100 µM and 1 mM showed a Michaelis–Menten-like profile. f The kcat values of TbGMPR (open circles) and TbGMPR∆CBS (closed circles) were plotted against the concentrations of GMP. The inset shows the data at low concentrations of GMP. Data were obtained from three independent experiments (n = 3). Each data point represents a mean ± s.d. in error bars. Source data are provided as a Source Data file.
