Table 3.
Table showing kinetic parameters of APT and AHMP.
| Inhibitor | Substrate | Km (μM) | Mechanism of inhibition | Ki (μM) | kcat(min)-1 |
| APT | Xanthine | 2.65 ± 0.02 | Competitive | 6.61 ± 0.28 | 114.54 ± 0.24 |
| 6MP | 6.01 ± 0.03 | Competitive | 1.30 ± 0.09 | 2.85 ± 0.02 | |
| AHMP | Xanthine | 2.71 ± 0.05 | Mixed | 5.7 ± 0.48(Ki2) (Competitive) 6.24 ± 0.04 (KI2) (Non-competitive) |
128.57 ± 0.45 |
| 6MP | 4.89 ± 0.04 | Mixed | 0.96 ± 0.01(Ki2) (Competitive) 0.98 ± 0.06 (KI2) (Non-competitive) |
3.64 ± 0.04 |
The reaction mixture comprised of 1 ml of 0.2 M, sodium phosphate buffer pH 7.4 containing 10 μM of either xanthine or 6MP. The reaction was initiated by the addition of 2.8 U/ml of bovine XOD.
Ki2 = Inhibition constant for competitive inhibition mechanism exhibited by AHMP
KI2 = Inhibition constant for non-competitive inhibition mechanism exhibited by AHMP