TABLE 5.
Evaluation of enzyme inhibitors in biochemical assays
| Inhibitors | Inhibition (IC50) of enzyme activities (μM)a,b of: |
|||||
|---|---|---|---|---|---|---|
| CES1b | CES1c | CES2 | CatAc |
HINT1 | ||
| pH 6.5 | pH 5.5 | |||||
| BNPP | 0.75 ± 0.12 | 14.0 ± 5.6 | 1.2 ± 0.2 | >100 | >100 | >100 |
| Telaprevir | >100 | >100 | >100 | 0.078 ± 0.009 | 0.34 ± 0.06 | >100 |
| TrpGc | >100 | >100 | >100 | >100 | >100 | 1.5 ± 0.5 |
| Compound 7 | >100 | >100 | >100 | >100 | >100 | 0.16 ± 0.05 |
a
Values represent the average ± standard deviation of three independent measurements.
b
Substrates for CES isozymes, CatA, and HINT1 were 4-NPA (4-nitrophenyl acetate), fluorogenic peptide [MCA-Arg-Pro-Pro-Gly Phe-Ser-Ala-Phe-Lys(DNP)-OH], and RDV MetX, respectively.
c
CatA assay was conducted under both pH 6.5 and pH 5.5. The pH 6.5 condition was used to minimize potential acid hydrolysis of RDV. The pH 5.5 condition was used to resemble the native acidic lysosomal environment for this enzyme.