Biochemical potency of CB-1158 against arginase and NOS activity
| CB-1158, IC50 (nM) | |
|---|---|
| Purified enzyme assay | |
| Recombinant human Arg1 | 86 (±25) |
| Recombinant human Arg2 | 296 (±5) |
| Recombinant bovine endothelial NOS | N/A |
| Rat cerebellar neuronal NOS | N/A |
| Recombinant murine inducible NOS | N/A |
| Cell lysate assay | |
| Human granulocyte lysate | 178 (±28) |
| Human erythrocyte lysate | 116 |
| Human hepatocyte lysate | 158 (±23) |
| Cancer patient plasma | 122 (±32) |
Mean IC50 values in nanomolar for CB-1158 inhibition of purified recombinant arginases or native arginases in cell lysates or cancer patient plasma. Standard deviations are indicated in parentheses. Recombinant Arg1 assays (N = 3) were performed in duplicate wells in the presence of 160 μM L-arginine. Recombinant Arg2 assays (N = 2) were performed in triplicate wells with 20 mM L-arginine. Arginase activity assays using human granulocyte lysate (N = 3), human erythrocyte lysate (N = 1), human hepatocyte lysate (N = 4), and cancer patient plasma (N = 5) were performed in duplicate wells with 160 μM L-arginine. Purified NOS enzyme activity was assayed in the presence 50 μM CB-1158, which showed no inhibitory activity against the three NOS isoforms
N/A not applicable