Table 1.
Kinectic parameters for purified APN from A. pisum. Relative values of k cat/K m were calculated using LeupNA as reference for synthetic substrate. For peptide subtrates, PheGlyGlyPhe was used as reference. The values were determined at least twice by 10 independent determinations with different substrate concentrations. SEM values were calculated by fitting data by a weighted linear regression using the software SigmaPlot®. AlaβNA, l‐alanine‐β‐naphthylamide; AlapNA, l‐alanine‐p‐nitroanilide; ArgpNA, l‐arginine‐p‐nitroanilide; MetβNA, l‐methionine‐β‐naphthylamide; MetpNA, l‐methionine‐p‐nitroanilide; ProβNA, l‐proline‐β‐naphthylamide.
| Substrate | K m (mm) | k cat (s−1) | k cat/K m (mm −1·s−1) | k cat/K m (relative) |
|---|---|---|---|---|
| LeupNA | 0.057 ± 0.007 | 119 ± 15 | 2090 ± 360 | 100 |
| MetpNA | 0.026 ± 0.008 | 45 ± 3 | 1720 ± 540 | 80.2 |
| ArgpNA | 0.19 ± 0.02 | 158 ± 31 | 832 ± 180 | 40.5 |
| AlapNA | 1.1 ± 0.04 | 222 ± 4 | 202 ± 9 | 9.9 |
| LeuβNA | 0.038 ± 0.003 | 105 ± 2 | 2760 ± 220 | 133 |
| ArgβNA | 0.058 ± 0.06 | 72 ± 2 | 1220 ± 130 | 59.0 |
| MetβNA | 0.043 ± 0.005 | 28 ± 1 | 642 ± 76 | 30.9 |
| AlaβNA | 0.28 ± 0.04 | 67 ± 2 | 240 ± 8 | 11.4 |
| ProβNA | 1.6 ± 0.2 | 6.8 ± 0.2 | 4.3 ± 0.5 | 0.2 |
| AspβNA | – | < 0,19 | ||
| LeuGly | 0.26 ± 0.08 | 5.6 ± 0.4 | 22 ± 7 | 11.1 |
| LeuGlyGly | 0.28 ± 0.06 | 26 ± 2 | 92 ± 20 | 48.9 |
| LeuGlyGlyGly | 0.9 ± 0.1 | 16 ± 1 | 19 ± 2 | 10 |
| LeuGlyGlyGlyGly | 1.1 ± 0.1 | 17 ± 1 | 15 ± 1 | 7.8 |
| LeuLeuLeu | 0.070 ± 0.02 | 6.4 ± 0.3 | 91 ± 23 | 47.8 |
| PheGly | 0.60 ± 0.08 | 13 ± 4 | 22 ± 8 | 11.1 |
| PheGlyGly | 1.1 ± 0.3 | 23 ± 2 | 22 ± 6 | 11.1 |
| PheGlyPheGly | 0.71 ± 0.07 | 92 ± 2 | 130 ± 13 | 68.8 |
| PheGlyGlyPhe | 0.27 ± 0.03 | 50 ± 2 | 188 ± 21 | 100 |