TABLE 3.
Enzyme kinetic parameters for the conversion of 6-mercaptopurine to 6-thioxanthine by purified recombinant human aldehyde oxidase and 6-thioxanthine to 6-thiouric acid by E. coli lysate containing recombinant human xanthine oxidase
Data are representative of at least duplicate measurements ± S.E.M.
| Reaction | Source | Enzyme Kinetics |
Vmax |
Kcat |
Km |
Ki | ||
|---|---|---|---|---|---|---|---|---|
| Vmax1 | Vmax2 | Km1 | Km2 | |||||
| nmol/min per milligram | min−1 | μM | μM | |||||
| 6MP → 6TX | Purified human AO | Substrate Inhibition | NA | NA | 0.2 ± 0.0 | 572 ± 172 | NA | 244 ± 77 |
| 6TX → 6TUA | Human XO containing E. coli lysate | Michaelis-Menten | NA | NA | NA | 30 ± 2 | NA | NA |