Table 2. Rates of hydrolysis of physiological peptides by NEP mutants.
leu-ENK | Insulin B Chain | Aß1–40 | |
pmole/min/ng | pmole/min/ng | fmole/min/ng | |
NEP | 1.90±0.23 | 0.86±0.13 | 198±12 |
NEPF563L | 1.57±0.32 | 1.17±0.18 | 116±4 |
NEPF563M | 1.21±0.22 | 0.21±0.01 | 85±3 |
NEPS546E | 1.12±0.12 | 0.58±0.07 | 93±8 |
NEPF563I | 1.06±0.17 | 0.13±0.02 | 43±1 |
NEPF563V | 0.31±0.02 | 0.06±0.02 | 14±1 |
Hydrolysis was carried out at 37°C at in 20 mM MES buffer, pH 6.5. Substrate concentrations were 15 µM insulin B chain, 24 µM Aß1–40, and 64 µM leu-ENK. Activity was determined by following the disappearance of substrate by HPLC. Each reaction was run in at least triplicate. Statistical analysis was conducted using a two-tailed paired t-test with Prism4 software.