Table III.
Enzymatic kinetic parameters of MsrB2 using N-acetyl-MetSO and free MetSO as substrates by following NADPH oxidation in the presence of the Trx reducing system
Apparent Km for Trx h1, MetSO, or N-acetyl-MetSO were determined at saturating concentration of the other substrate. KSulfoxide and kcat/KSulfoxide should be respectively divided and multiplied by two, considering that only the R isomer is a substrate of MsrB.
| KSulfoxide | kcat | kcat/KSulfoxide | KTrx h1 | |
|---|---|---|---|---|
| mm | s−1 | m−1s−1 | μm | |
| Free MetSO | 28.980 ± 4.98 | 1.37 ± 0.07 | 47 ± 2 | 8.32 ± 1.44 |
| N-acetyl-MetSO | 2.16 ± 0.28 | 2.94 ± 0.12 | 1,361 ± 55 |