Table 3.
Epoxidase activity of VpStyA2B-mutants and -wildtype enzymes.
| Substrate | Styrene | Indole | ||
|---|---|---|---|---|
| SMO 1 | Vmax (mU mg−1) | ETY 2 (%) | Vmax (mU mg−1) + Extra RoStyBart 3 | Plate Screening 4 |
| wildtype VpStyA1 | n.a. | n.a. | 460 | +++ |
| wildtype VpStyA2B | 159 | 1 | 140 | ++ |
| 408-TIVVV | 135 | 4.4 | 327 | + |
| 408-AAAAA | 260 | 3 | 260 | +++ |
| 408-HHHHH | <1 | <1 | 4 | + |
| 408-WYHHH | 1.7 | <1 | 7.3 | + |
| 408-WYHHHHH | <1 | <1 | 1.6 | + |
| 408-GQWCSQY | <1 | <1 | 3.1 | + |
1 Mutants are made of VpStyA2B as described in methods and were in analogy to the wildtype investigated. 2 The electron transfer yield (ETY) was calculated from the NADH-consumption vs. epoxidation rate. 3 In case of StyA1 an additional NADH:FAD oxidoreductase was needed (here RoStyBart) which could also assist StyA2B-like proteins [6,24]. 4 The plate screening was performed with clones expressing respective genes on an agar plate and the indigo formation (+ little, ++ normal, and +++ significant indigo formed) was followed online by a camera. n.a. = no activity measureable.