Table 1B.
Kinetic constants for cleavage of the fluorogenic substrate Ala-Pro-AFC and the chromogenic substrate Gly-Pro-pNA by wild-type DPPIV and DPPIV glycosylation mutants (proteins expressed in Hi5 insect cells)
| DPPIV mutant | Km (μM) | kcat (s−1) | kcat/Km (M−1 s−1) | Relative kcat/Km |
| Kinetic constants for cleavage of Ala-Pro-AFC | ||||
| Wild-type DPPIV | 16 | 23 | 1.4 × 106 | 1.0 |
| DPPIV-N85A | 16 | 27 | 1.7 × 106 | 1.2 |
| DPPIV-N92A | 17 | 31 | 1.9 × 106 | 1.4 |
| DPPIV-N150A | 17 | 37 | 2.2 × 106 | 1.6 |
| DPPIV-N219A | 19 | 42 | 2.2 × 106 | 1.6 |
| DPPIV-N229A | 15 | 40 | 2.7 × 106 | 1.9 |
| DPPIV-N281A | 20 | 40 | 2.0 × 106 | 1.4 |
| DPPIV-N321A | 18 | 34 | 1.8 × 106 | 1.3 |
| DPPIV-N520A | 17 | 36 | 2.1 × 106 | 1.5 |
| DPPIV-N685A | 15 | 30 | 1.9 × 106 | 1.4 |
| Kinetic constants for cleavage of Gly-Pro-pNA | ||||
| Wild-type DDPIV | 138 | 24 | 1.7 × 105 | 1.0 |
| DPPIV-N85A | 149 | 30 | 2.0 × 105 | 1.2 |
| DPPIV-N92A | 143 | 34 | 2.4 × 105 | 1.4 |
| DPPIV-N150A | 151 | 40 | 2.6 × 105 | 1.5 |
| DPPIV-N219A | 160 | 45 | 2.8 × 105 | 1.6 |
| DPPIV-N229A | 145 | 43 | 3.0 × 105 | 1.8 |
| DPPIV-N281A | 168 | 43 | 2.5 × 105 | 1.5 |
| DPPIV-N321A | 146 | 35 | 2.4 × 105 | 1.4 |
| DPPIV-N520A | 131 | 35 | 2.7 × 105 | 1.6 |
| DPPIV-N685A | 142 | 32 | 2.2 × 105 | 1.3 |