Table 2.
Activity of Semisynthetic and Mutant Enzymes Towards Thioredoxin
| Enzyme | kcat (min−1) | Km (μM) |
|---|---|---|
| a TR-Gly487 | No activity | No activity |
| b TRSec489Cys | 1.2 ± 0.11 | 6.6 ± 1.8 |
| TR-semisynthetic (63% Se) | 1500 ± 81 | 35 ± 5 |
| c TR-semisynthetic (91% Se) | 2220 ± 78 | 67.6 ± 6 |
| d rat TR1 | 2500 | 3.3 |
a
The truncated enzyme ends at glycine 487 and is missing the C-terminal tripeptide.
b
The full-length mutant in which cysteine replaces the catalytic selenocysteine residue.
c
Data from optimized procedure using a higher ratio of peptide to protein as described under Methods.
d
Taken from (35).