TABLE 1.
Substrate specificity of crude enzyme extract containing wild-type or D227A mutant MPH(2′)II
| Macrolide | Relative activity (%)a
|
|
|---|---|---|
| Wild type | D227A mutant | |
| 14 membered | ||
| Oleandomycin | 100 | 100 |
| Troleandomycin | 104 | 58 |
| Erythromycin | 83 | 83 |
| Clarithromycin | 46 | 49 |
| Roxithromycin | 50 | 9 |
| 15 membered azithromycin | 88 | 27 |
| 16 membered | ||
| Kitasamycin | 202 | 16 |
| Spiramycin | 75 | 85 |
| Josamycin | 75 | 2 |
| Rokitamycin | 50 | 2 |
| Tylosin | 55 | 13 |
a
The specific activity of the wild type enzyme for oleandomycin was 121 nmol/h/mg of protein and that of the D227A mutant was 8.5 nmol/h/mg of protein.