Table IV. Effect of proteasome inhibitors on the digestion of the 30-mer substrate.
| No Inhibitor | MG-132 | Epoxomicin | |
|---|---|---|---|
| Amount digested | 75.8% | 56.8% | 49.9% |
| N. of digestion products | 21 | 18 | 13 |
| Peptides involving dual cleavagea | 13 (61.9%) | 8 (44.4%) | 8 (61.5%) |
| N. of cleaved peptide bondsb | 22 (75.9%) | 23 (79.3%) | 18 (62.1%) |
| N. of productive species for the ligandc | 1 | 1 | 0 |
| Relative yield of productive cleavagesd | 16.8% | 9.0% | 0 |
| N. of destructive cleavages for the ligande | 6 (27.3%) | 6 (26.1%) | 4 (22.2%) |
| Relative yield of the destructive cleavagesd | 19.8% | 21.0% | 25.9% |
| Destruction/production ratio for the ligandf | 1.2 | 2.3 | – |
a Percent relative to the total number of digestion products.
b Percent relative to the total number of peptide bonds in the substrate.
c Peptides with the right C-terminus and right or extended N-terminus. Percent values are relative to the total number of digestion products.
d Added values from Table VIIS. Productive cleavages correspond to cleavage after R14.
e Cleaved peptide bonds implying destruction of the epitope. Percent values are relative to the total number of cleaved peptide bonds.
f Ratio between the joint relative yield of cleavages implying destruction of the natural ligand and that of the potentially productive peptides.