TABLE 2.
Results of best-fit nonlinear least squares regression of the kinetic mode of inhibition data for the inhibitor to the steady-state ordered rate equation including substrate inhibition by both substrates and competition by compound 1 with both substrates
The data were fit to models in which acetyl-CoA or d-glucosamine 1-phosphate is substrate A, i.e. the first substrate to bind. The difference in χ2 values for the two regressions did not reach statistical significance (p = 0.22).
| Kinetic constant | Substrate A |
|
|---|---|---|
| Acetyl-CoA | d-Glucosamine 1-phosphate | |
| Vmax (ΔA412) | 1.49 ± 0.03 | 1.48 ± 0.03 |
| Kia (μm) | 24 ± 2 | 25 ± 3 |
| KmA (μm) | 398 ± 15 | 290 ± 2 |
| KmB (μm) | 311 ± 11 | 423 ± 16 |
| KsiA (μm) | 2050 ± 190 | 965 ± 40 |
| KsiB (μm) | 881 ± 36 | 2400 ± 280 |
| KI1 (μm) (substrate A competitive) | 0.79 ± 0.02 | 7.1 ± 0.5 |
| KI2 (μm) (substrate B competitive) | none | 0.86 ± 0.02 |
| χ2 | 0.48 | 0.44 |