Table 2.
Values of Km and kcat for the fluorogenic substrates FS1 (Glu[EDANS]ThrHisGlnValTry↓PheValArgLysAlaLys [DABCYL]-NH2) and FS2 (Glu[EDANS]ThrProGlnValTyr↓ PheValArgLysAlaLys [DABCYL]-NH2) and their chromogenic analogues CS1 (AlaThrHisGlnValTyr(p-nitro-Phe)ValArgLysAla) and CS2 (AlaThrProGlnValTyr(p-nitro-Phe)ValArgLysAla)
| Enzyme | Substrate | Km (μM) | kcat (sec−1) |
| MAV-PR(S) | FS1 | 2.2 ± 0.6 | 0.7 ± 0.1 |
| MAV-PR(S) | FS2 | 3.5 ± 0.5 | 8.6 ± 1.4 |
| MAV-PR(S) | CS1 | 75a | 5a |
| MAV-PR(S) | CS2 | 9a | 5a |
| HIV-1-PR(T) | FS1 | 3.0 ± 0.4 | 13.3 ± 1.4 |
| HIV-1-PR(T) | CS1 | 15b | 14b |
| HIV-1-PR(S) | FS1 | 4.2 ± 1.2 | 4.8 ± 0.7 |
| MPMV-PR(T) | FS1 | 0.9 ± 0.1 | 1.9 ± 0.2 |
| MPMV-PR(T) | CS1 | 60c | 0.17c |
For experimental details see Materials and Methods. Several values were adopted from aKonvalinka et al. (1991); bKonvalinka et al. (1990); and cZábranský (1999).