Table 1. Stability constants K and half saturation constants K s for chloroquine and related blocker-substrates to PA-channels, when added to the cis-side of lipid bilayer membranes.
| Heterocyclic compound | K [L/mol] | KS [mmol/L] |
| HA 42 | 1460 | 0.69 |
| HA 47 | 500 | 1.99 |
| HA 112 | 18,500 | 0.057 |
| HA 486 | 38,000 | 0.027 |
| HA 708 | 11,300 | 0.089 |
| HA 728 | 11,800 | 0.085 |
| HA 766 | 29,400 | 0.036 |
| HA 1196 | 3,800 | 0.26 |
| HA 1212 | 7,000 | 0.15 |
| HA 1221 | 6,000 | 0.17 |
| HA 1371 | 3,200 | 0.31 |
| HA 1383 | 749,000 | 0.0013 |
| HA 1495 | 274,000 | 0.0036 |
| HA 1504 | 82,900 | 0.012 |
| HA 1568 | 478,000 | 0.0027 |
| HA 1882 | 7,900 | 0.13 |
| HA 1885 | 10,800 | 0.11 |
| Chloroquine | 676,000 | 0.0015 |
The data represent means of at least three individual titration experiments. K s values from chloroquine are given for comparison and were taken from [31]. Membranes were formed from diphytanoyl phosphatidylcholine/n-decane. The aqueous phase contained 150 mM KCl, 10 mM MES, pH 6.0, and about 1 ng/ml PA63; T = 20°C.