Table 2.
Kinetic constants for PAD substrates
| Substrate | Km (µM) |
Relative Vmax (%) |
kcat (sec−1) |
kcat/Km (µM−1sec−1) |
|---|---|---|---|---|
| L-Arginine | (1.2 ± 0.5)×103 | 100 | 0.22 | 1.9×10−4 |
| Nα-Benzoyl-L-arginine (Nα-BA) | 10–20 | 54.5 | 0.12 | (6–12)×10−3 |
| D-Arginine | (1.9 ± 0.5)×103 | 26.4 | 0.058 | 3.1×10−5 |
| BK (R-P-P-G-F-S-P-F-R) | 21 ± 1 | 18.8 | 0.043 | 2.1×10−3 |
| BK antagonist (K-R-P-P-G-F-S-P-L) | 33 ±1 | 3.1 | 6.8×10−3 | 2.1×10−4 |
| P-R-F | 70 ± 1 | 3.4 | 7.5×10−3 | 1.1×10−4 |
| P-F-R | 89 ± 1 | 78.2 | 0.17 | 1.9×10−3 |
| L-Canavanine | (6 ± 1)×103 | 2.5 | 5.2×10−3 | 9.3×10−7 |
| L-Arginine hydroxamate | (6.9 ± 0.5)×103 | 68.2 | 0.15 | 2.2×10−5 |
| Benzoyl arginine ethyl ester (BAEE) | (18 ± 1)×103 | 8.1 | 0.019 | 9.9×10−7 |
| Agmatine | (31 ± 1)×103 | 3.2 | 7.0×10−3 | 2.3×10−7 |
| Homoarginine | (4.7 ± 0.8)×103 | 50 | 0.11 | 2.4×10−5 |
| Nω-Hydroxy-L-arginine | (1.5 ± 0.5)×103 | 2.1 | 4.6×10−3 | 3.0×10−6 |
| Nω,Nω-Dimethyl-L-arginine | >1×106 a | <0.0017 |
a
No activity detected with 100mM Nω,Nω-dimethyl-L-arginine. Products from Nω-hydroxy-L-arginine and Nω, Nω-dimethyl-L-arginine have been previously measured using the citrulline colorimetric assay [33].