Skip to main content
. 2013 Dec 26;8(12):e83091. doi: 10.1371/journal.pone.0083091

Figure 2. Enzymatic activity of TtMDH.

Figure 2

(A) Effect of pH on TtMDH enzymatic activity measured with 100 mM glycine-NaOH buffer of pH 8.5–11.0 under standard assay conditions. All TtMDH activity values were obtained from the means of independent experiments. Specific activity is expressed as units per mg protein; 1 unit is defined as 1 μmole NADH comsumed per minute. (B) Kinetic analysis of TtMDH. The initial enzymatic reaction velocity was measured at 0.15 mM NADH with oxaloacetate concentration from 2–0.015 mM in glycine-NaOH buffer (pH 10.0) at 37°C. The K M, Vmax and k cat values were calculated from Lineweaver-Burk plots (the double-reciprocal plot showed in the inset). (C) Temperature profile of TtMDH. The optimum temperature for enzyme activity was determined by measuring TtMDH activity at various temperatures from 37°C to 95°C under standard assay condition. All values of TtMDH activity were obtained from the means of three independent experiments. Specific activity is expressed as units per mg protein; 1 unit is defined as 1 μmole NADH consumed per minute.