Table 1.
Kinetic parameters of Pseudomonas putida and mammalian aromatic amino acid decarboxylases (AAAD) and insect 3,4-dihydroxyphenylalanine decarboxylase (DDC) for the two natural substrates L-3,4-dihydroxyphenylalanine (L-dopa) and 5-hydroxytryptophan (5-HTP).
| AAAD or DDC from different organisms | Substrates | Km (mM) | kcat (s−1) | kcat/Km (mM−1s−1) | References |
|---|---|---|---|---|---|
| Pseudomonas putida | L-dopa | 0.092 | 1.8 | 21 | Koyanagi et al., 2012 |
| AAAD | 5-HTP | 0.93 | 0.095 | 0.1 | |
| Hog kidney AAAD | L-dopa | 0.19 | 8.0 | 42 | Data from Christenson et al. (1970) and kcat values were calculated by Koyanagi et al. (2012) |
| 5-HTP | 0.1 | 0.77 | 7.7 | ||
| Rat liver AAAD | L-dopa | 0.086 | 5 | 58 | Hayashi et al., 1993 |
| Rat recombinant AAAD with His-Tag | L-dopa | 0.14 | 7 | 50 | Data from Jebai et al. (1997), kcat values were calculated based on the Vmax values with the reported 50 kDa molecular mass |
| 5-HTP | 0.066 | 1.5 | 23 | ||
| Drosophila melanogaster DDC | L-dopa | 2.2 | 4.7 | 2.1 | Han et al., 2010b |
| 5-HTP | 0.4 | 1.0 | 2.5 |