TABLE 4.
Kinetic analysis of gB-2 binding to candidate topical microbicidesa
| Microbicide | Ka (M−1 s−1) | Kd (s−1) | KD (kd/Ka) (M) |
|---|---|---|---|
| PRO 2000 | 1,340 | 8.71 × 10−4 | 6.5 × 10−7 |
| PSS | 159,000 | 1.5 × 10−3 | 9.41 × 10−9 |
| PMHS | 26,900 | 5.3 × 10−4 | 1.97 × 10−8 |
| SAMMA | 183 | 4.61 × 10−3 | 2.52 × 10−5 |
a
The doses tested for each compound were (i) 3.125, 6.25, 12.5, 25, 50, 75, 100, and 200 μg/ml for PRO 2000; (ii) 62.5, 125, and 250 μg/ml for PSS; (iii) 0.825, 1.65, 3.3, 6.6, 13.2, 26.4, 52.8, and 105.6 μg/ml for PMHS; and (iv) 1, 50, 100, 200, 500, and 1,000 μg/ml for SAMMA. Binding signals were corrected for nonspecific binding by subtracting the signal of the control flow cell. The rate of association (Ka), rate of dissociation (Kd), and affinity constant (KD) were calculated by using the 1:1 Langmuir binding model in the BIA evaluation software.