Table 1.
Characteristics of destabilizing mutations engineered into E. coli β-galactosidase
| Mutant | |||||
|---|---|---|---|---|---|
| V567D | F758S | I141N | G353D | A880E | |
| Predicted ΔΔG (kcal/mol) | -2.6 | -2.9 | -2.4 | -1.6 | -0.6 |
| Relative protein activity (%) | 31 | 4 | 17 | 2 | 61 |
| Codon substitution (WT/mutant) | GTC/GAC | TTT/TCT | ATT/AAT | GGC/GAC | GCG/GAG |
| Codon preference % (WT/mutant) | 13.5/53.9 | 29.0/32.4 | 33.5/17.3 | 42.8/53.9 | 32.3/24.7 |
| Found in inclusion bodies (see Figure 1a) | No | Yes | Yes | Yes | No |
In the table, ΔΔG values represent destabilizing effects predicted by the I-Mutant2.0 server [32]. The experimentally determined enzymatic activities of the mutants (in percentages) are shown in the table relative to WT.