Table 1.
Presteady state kinetics of single turnover reactions of hamster NAT2 acetylation by PNPA
| Hamster NAT2 | Kmacetyl (mM) | k2 (s−1) | k2/Kmacetyl (M−1·s−1) | khydrolysis (s−1) | T1/2(s) |
|---|---|---|---|---|---|
| WTa | 9 ± 5.7a | 1301± 716a | (1.4 ± 0.05)×105a | (7.9 ± 0.7)×10−3a | 88 ± 8a |
| Y190F | 3.5 ± 1.1 | 279 ± 54 | (8.0 ± 3.9)×104 | (28 ± 0.4)×10−3 | 25 ± 3 |
| Y190I | 4.1 ± 0.7 | 57 ± 6 | (1.4 ± 0.04)×104 | (230 ± 40)×10−3 | 1.9 ± 0.1 |
| Y190A | 2.8 ± 0.7 | 15 ± 3 | (5.5 ± 2.3)×103 | (37 ± 8)×10−3 | 19 ± 0.4 |
khydrolysis, the hydrolysis rate constant of the acetylated enzyme intermediate;
T1/2, the half life time of the acetyl-enzyme intermediate.
a
Values for the “wild type” protein are taken from previously published research articles: [26]