TABLE 3.
Substrate specificity of purified 12α-HSDHs
| Substratea | Cofactor | rCSCIb |
rCHYLb |
rCHIRb |
|||
|---|---|---|---|---|---|---|---|
| Activity | Relative activity (%) | Activity | Relative activity (%) | Activity | Relative activity (%) | ||
| 12-oxoLCA | NADPH | 38.59 ± 2.38 | 100 | 79.42 ± 3.58 | 100 | 133.56 ± 4.91 | 100 |
| 12-oxoLCA | NADH | NA | NA | NA | NA | NA | NA |
| 12-oxoCDCA | NADPH | 3.69 ± 0.12 | 9.55 | 3.31 ± 0.11 | 4.16 | 4.88 ± 0.16 | 3.65 |
| DCA | NADP+ | 153.42 ± 6.2 | 100 | 127.68 ± 3.50 | 100 | 239.16 ± 2.89 | 100 |
| CA | NADP+ | 83.55 ± 1.55 | 54.44 | 102.79 ± 2.85 | 80.51 | 196.87 ± 4.36 | 82.32 |
| TDCA | NADP+ | 9.28 ± 0.57 | 6.05 | 57.56 ± 1.78 | 45.08 | 96.45 ± 6.48 | 40.33 |
| GDCA | NADP+ | 9.76 ± 1.56 | 6.36 | 30.86 ± 0.67 | 24.17 | 61.81 ± 3.61 | 25.85 |
| CDCA | NADP+ | NA | NA | NA | NA | NA | NA |
| DCA | NAD+ | NA | NA | NA | NA | NA | NA |
a
12-oxoLCA, 12-oxolithocholic acid; 12-oxoCDCA, 12-oxochenodeoxycholic acid; DCA, deoxycholic acid; CA, cholic acid; TDCA, taurodeoxycholic acid; GDCA, glycodeoxycholic acid; CDCA, chenodeoxycholic acid. For both the reductive and oxidative directions, the highest activity was set to 100%. The concentrations used in the assays were based on Km values (refer to Materials and Methods).
b
Values represent the means ± SD based on three or more replications. NA, no activity detected.