Table 1. Binding constants of AR-R17477 for wild-type and mutant NOS isoforms.
| Kd, μM
|
Critical residue
|
|||
|---|---|---|---|---|
| Protein | -H4B | +H4B | IC50, μM (16) | |
| Holoenzyme | ||||
| Rat nNOS | ND | 0.035 | 0.035 | L337 |
| Mouse iNOS | 5.0 | N115 | ||
| Human iNOS | ND | 0.15 | T121 | |
| Human eNOS | 3.5 | F105 | ||
| Oxygenase domains | ||||
| Mouse iNOSoxy | 2.5 | 0.50 | N115 | |
| Mouse iNOSoxy N115L | 1.2-1.4 | 0.09 | L115 | |
| Human iNOSoxy | 1.75 | 0.25 | T121 | |
| Human iNOSoxy T121L | 1.3 | 0.08 | L121 | |
| Rat nNOSoxy | 0.06 | 0.02 | L337 | |
| Rat nNOSoxy L337N | 1.2 | 1.5-2.0* | N337 | |
| Rat nNOSoxy L337F | ND | 2-3 | F337 | |
ND, not determined.
*
Spectral pertubation analysis was performed in the presence of 5 mM imidazole, because Kd (imidazole) is higher (400 μM) compared to wild-type nNOSoxy (80 μM).