Table IV.
Effects on the Rate of Conversion of Active PAI-1 to the Latent Form in the Presence of Mixtures of Type I and Type II Metals
| Additive | Total metal | Free metal | klat (s−1) | t1/2 (h) |
|---|---|---|---|---|
| MgCl2 | 500 μM | ∼400 μM | 1.23 (±0.01) × 10−5 | 15.7 (±0.1) |
| NiCl2 | 2000 μM | 73 μM | 20.5 (±0.8) × 10−5 | 0.94 (±0.03) |
| CuCl2 | 135 μM | 0.24 μM | 2.39 (±0.14) × 10−5 | 8.1 (±0.5) |
| CuCl2 and NiCl2 | Above | Above | 7.67 (±0.11) × 10−5 | 2.51 (±0.04) |
| CuCl2 and MgCl2 | Above | Above | 1.22 (±0.05) × 10−5 | 15.7 (±0.7) |
The values for klat and the associated t1/2 at 20°C were calculated from kinetic experiments that measure the rate of loss over time of PAI-1 antiprotease activity using tPA (Fig. 5).