Table I.
Substrate specificities of recombinant forms of DAT and MAT, as determined from TLC scrapings of the major radioactive bands
| Substrateb | Activitya
|
|
|---|---|---|
| rDAT | rMAT | |
| % | ||
| Deacetylvindoline | 100 | 48 |
| Crude hairy root alkaloid | NAc | 100 |
| Tabersonine | NA | NA |
| 16-MeOH-tabersonine | NA | NA |
| 3-OH-tabersonine | NA | NA |
| n-CH3-3-OH-tabersonine | NA | NA |
| 2,3-Dihydro-tabersonine | NA | NA |
| 6,7-Dihydro-3-OH- tabersonine | NA | NA |
| Hörhammericine | NA | 40 |
| Lochnericine | NA | NA |
100% activity refers to a total radioactivity count of 36,367 dpm for rDAT and 2,233 dpm for reactivated rMAT reaction products, respectively.
Assays were carried out as described in experimental procedures, containing either 0.17 μg of rDAT or 6.0 μg of rMAT, respectively, along with 20 μM deacetylvindoline, 20 μL of crude hairy root alkaloid extract, approximately 10 μg of each respective alkaloid, or 20 μg of hörhammericine or lochnericine, respectively, as substrate in a final assay volume of 100 μL containing 1% (v/v) DMSO (final concentration) as the substrate solvent.
NA, Not accepted as a substrate.