Conversion of tenofovir prodrugs by serine, cysteine, and aspartic proteases
Substrates (100 μM) were incubated with each tested enzyme under the reaction conditions described under Materials and Methods. The reaction products were analyzed by ion-pairing HPLC. Data are means from at least two independent determinations; S.D. values were <20% of the mean.
Amidate Moiety | GS-7003 Phe-Me | GS-7098 Leu-Me | GS-7340 Ala-iPr | GS-7095 Ile-Me | GS-7096 Val-Me | GS-7119 Gly-Et | GS-7120 ABA-Et |
|---|---|---|---|---|---|---|---|
| pmol/min/μg | |||||||
| Serine proteases | |||||||
| Chymotrypsin | 4138 | 604 | 0 | 0 | 0 | 123 | 22 |
| Cathepsin G | 8144 | 995 | 0 | 0 | 0 | 0 | 0 |
| Chymase | 4961 | 369 | 0 | 0 | 0 | 168 | 10 |
| Leukocyte elastase | 0 | 0 | 891 | 327 | 194 | 0 | 181 |
| Proteinase 3 | 0 | 0 | 57 | 165 | 0 | 0 | 70 |
| Pacreatic Elastase I | 0 | 85 | 113 | 53 | 24 | 23 | 756 |
| Granzyme A | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Trypsin | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Granzyme B | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Cathepsin Aa | 4400 | 0 | 31,000 | 0 | 0 | 2449 | 2900 |
| Cysteine proteases | |||||||
| Cathepsin H | 34 | 0 | 27 | 0 | 0 | 12 | 10 |
| Cathepsin B | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Cathepsin C | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Cathepsin L | 0 | 26 | 0 | 0 | 0 | 0 | 44 |
| Aspartic proteases | |||||||
| Cathepsin D | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Serine hydrolases | |||||||
| Porcine liver carboxylesterase | 73 | 10 | 116 | 0 | 1 | 67 | 44 |
| Cellular extract | 6.8 | 0 | 21.5 | 0.2 | 0.2 | 3.7 | 5.3 |