Table 1. Kinetic parameters of AeAGT and hAGT towards alanine, kynurenine, 3-HK (DL form) and comparison with previously reported parameters for AeHKT and DrAGT [21].
Amino acids were assayed with glyoxylate as the amino group acceptor. Kynurenine and 3-HK were tested from 0.2 to 10 mM, and alanine was tested from 0.6 to 80 mM. Data are derived from non-linear regression analysis by using the Enzyme Kinetics Module in SigmaPlot 8.2 and the errors represent the S.E. from regression.
| Substrate | Km (mM) | kcat (s−1) | kcat/Km (M−1·s−1) | |
|---|---|---|---|---|
| AeAGT | Alanine | 34±10 | 117±15 | 3450 |
| hAGT | Alanine | 15±2 | 53±3 | 3483 |
| Kynurenine | 5.4±1.7 | 4.3±0.8 | 800 | |
| 3-HK | 9.5±3.9 | 4.4±1 | 450 | |
| AeHKT | Alanine | 18±2 | 20±1 | 1117 |
| Kynurenine | 3.7±0.2 | 12±3.7 | 3250 | |
| 3-HK | 2.6±0.6 | 34.2±5.3 | 13150 | |
| DrAGT | Alanine | 149±44 | 131±20 | 879 |