Table 1.
Kinetic analysis of recombinant T. kodakaraensis malic enzyme (Tk-Mae). All cofactors and co-substrates were present at saturating concentrations. For oxidative decarboxylation, NADP+ was added at a concentration of 5 mM. For reductive carboxylation, NADPH and NaHCO3 were added at concentrations of 0.05 and 12.5 mM, respectively. For both reactions, Mn2+ was present at a concentration of 5 mM. Abbreviations: Km = Michaelis constant; Vmax = maximum velocity; and kcat/Km = catalytic efficiency.
| Substrate | Direction | Apparent | Vmax | kcat/Km |
| Km (mM) | (U mg–1) | (mM–1 s–1) | ||
| Malate | Oxidative | 16.9 | 7.1 | 0.32 |
| decarboxylation | ||||
| Pyruvate | Reductive | 7.3 | 4.5 | 0.46 |
| carboxylation | ||||