Table 2.
substrate | KM (μM) | kcat (s−1) | kcat/KM × 104 (M−1 s−1) | relative activity | preferred conform. |
---|---|---|---|---|---|
dU | 1.5 ± 1 | 0.7 ± 0.1 | 48 | 0.8 | C2′ -endo |
U | > 1000 | n.d. | - | - | C3′ -endo |
5-FdUrd | 1 ± 0.1 | 0.74 ± 0.05 | 74 | 2.5 | C2′ -endo |
ddT | 30 ± 5 | 0.33 ± 0.04 | 1.1 | 1.1 | C2′ -endo |
ddU | > 1000 | n.d. | - | - | C3′ -endo |
AZT | 0.65 ± 0.2 | 0.29 ± 0.03 | 45 | 1 | C3′ -endo |
d4T | 75 ± 5 | 0.41 ± 0.02 | 0.54 | 1.4 | planar |
DOT | 114 ± 15 | 0.29 ± 0.02 | 0.25 | 1 | C3′ -endo |
L-FMAU | 132 ± 4 | 0.5 ± 0.02 | 0.38 | 1.7 | C2′ -endo |
L-T | > 1000 | n.d. | - | - | C2′ -endo |
n.d. = not determined as vmax was not reached at 1000 μM substrate. dU: 2′-deoxyuridine, U: Uridine, ddT: 2′3′-dideoxythymidine, ddU: 2′3′-dideoxyuridine, 5FdUrd: 5-fluoro-2′-deoxyuridine, AZT: 2′,3′-dideoxy-3′-azidothymidine, d4T: 2′,3′-dideoxy-2′,3′-didehydrothymidine, L-FMAU: 2′-fluoro-5-methyl-β-L-arabinofuranosyluracil, L-T: L-thymidine, DOT: dioxolane thymidine