Figure 3
Kinetic analysis of the overall transaminase activity of recombinant purified AGXT2 for the L-alanine/glyoxylate and the L-homoarginine/pyruvate pairs.
Recombinant purified AGXT2 (0.01 mg/ml) was incubated with either 30 mM L-alanine and 1 mM glyoxylate (A) or 30 mM L-homoarginine and 1 mM pyruvate (B) in the presence of 100 μM PLP in 5 mM potassium phosphate buffer pH 8 + 0.15 M NaCl at 25 °C. At various times, aliquots were withdrawn and the reaction was stopped by adding 10% (v/v) TCA. The amount of ketoacid produced was determined by HPLC analysis. The rate of the overall transamination was determined from the linear fit of the data. Panels (C,D) show the rate of the overall transamination as a function of L-alanine or L-homoarginine concentration, respectively. The line is derived from the theoretical fit to the Michaelis-Menten equation.
