Table III.
Inhibitors | Concentrations | Activity (% of Control)
|
|||
---|---|---|---|---|---|
Chymotrypsin like (LLVY-AMC) | Trypsin like (GGR-βNA) | PGPH (LLE-βNA) | Caseinolytic 125I-casein | ||
ATP-Mg | 3 mm | 98 | 98 | 90 | 100 |
Poly-Lys | 0.1% (w/v) | 181 | 121 | 225 | 98 |
Hemin | 50 μm | 49 | 69 | 60 | 7 |
EDTA | 2 mm | 100 | 153 | 96 | 99 |
Indole-3-acetic acid | 0.5 mm | 90 | 91 | 96 | 103 |
E64 | 250 μm | 97 | 104 | 96 | – |
Chymostatin | 25 μm | 45 | 83 | 86 | – |
Phenylmethylsulfonyl fluoride (PMSF) | 5 mm | 80 | 44 | 82 | – |
MG132 | 5 μm | 27 | 10 | 100 | – |
12.5 μm | 19 | 0 | 100 | – | |
25 μm | 13 | 0 | 100 | – | |
50 μm | 7 | 0 | – | 37 | |
PI1 | 5 μm | 8 | 30 | – | 79 |
10 μm | 4 | 22 | 138 | 65 | |
20 μm | 0 | 14 | 124 | 62 | |
50 μm | 0 | 10 | 128 | 65 | |
100 μm | 0 | 5 | 123 | 67 | |
200 μm | 0 | 0 | 128 | 61 | |
SDS | 0.02% (w/v) | 176 | 52 | 320 | 156 |
Except with SDS, 20S proteasome (5 μg) was pre-incubated with different inhibitors or activators for 15 min before the addition of substrates. With SDS, substrates and SDS were added simultaneously. Activities are expressed as a percentage of the control (with solvent alone). Values are the mean of three to five independent experiments. sds are below 10%. –, Not determined.