Table 2.
Residual activity after heat shock of mutants of amino acid substitution to D3C/G283C MTG, and TG secretion
| Mutation | Enzyme | Residual Activity at 67 °C |
TG secretion |
|---|---|---|---|
| Ratio | mg/mL | ||
| Parent | D3C/G283C | 0.02 | 0.31 |
| Single | A | 0.04 | 0.33 |
| Double | Ab1 | 0.19 | 0.23 |
| Ab2 | 0.41 | 0.20 | |
| Triple | Ab1c1 | 0.45 | 0.45 |
| Ab1c2 | 0.47 | 0.44 | |
| Ab2c1 | 0.43 | 0.46 | |
| Ab2c2 | 0.53 | 0.45 | |
| Quadruple | Ab1c1D | 0.40 | 0.04 |
| Ab1c2D | 0.31 | 0.04 | |
| Ab2c1D | 0.49 | 0.24 | |
| Ab2c2D | 0.38 | 0.05 | |
| Fivefold | Ab1c1DE | N.D | 0.05 |
| Ab1c2DE | N.D | 0.03 | |
| Ab2c1DE | 0.02 | 0.20 | |
| Ab2c2DE | 0.03 | 0.29 | |
| Sixfold | Ab1c1DEF | N.D | 0.30 |
| Ab1c2DEF | N.D | 0.26 | |
| Ab2c1DEF | N.D | 0.20 | |
| Ab2c2DEF | N.D | 0.26 | |
| Sevenfold | Ab1c1DEFG | N.D | 0.23 |
| Ab1c2DEFG | 0.03 | 0.18 | |
| Ab2c1DEFG | 0.03 | 0.19 | |
| Ab2c2DEFG | 0.25 | 0.14 |
The ratio of residual activity was calculated between non-incubated sample and heat-shocked sample at 67°C for 10 min. Secreted protein was determined by analytical reverse-phase HPLC