Table 1. Biophysical and biochemical characteristics of recombinant wild-type and RCL mutants of α1-antitrypsin.
Variants were assessed for their midpoint of denaturation, SI and association rate constant (kass) against bovine α-chymotrypsin. The results are the mean of at least three independent experiments. n.i., non-inhibitory (less than 1% residual inhibitory activity).
| Variant | Tm (°C)* | SI† | kass (M−1 s−1) | kass•SI |
|---|---|---|---|---|
| ATC232S | 55.0 | 1.1±0.02 | 1.5±0.2×106 | 1.5×106 |
| P2P1′ | 55.0 | 100±9 | – | – |
| P6 | 54.5 | n.i. | – | – |
| P4 | 55.0 | n.i. | – | – |
| P6P4 | 55.0 | 89±7 | – | – |
| P10P8 | 56.0 | 4.56±0.32 | 1.2±0.2×105 | 5.7×105 |
| P14P12 | 57.0 | n.i. | – | – |
*All standard errors were less than precision of the technique on the instrument (±0.5°C).
†Standard errors were calculated by regression of a transformed linear equation with the intercept at the abscissa as a parameter.