Table 4. Effects of amino acid substitution on enzymatic parameters for EGFR-Y845 and ErbB4-Y1221 peptides.
The substituted residues are shown in italic bold. Results represent means±S.E.M.
| Km (μM) | kcat (min−1) | kcat/Km (min−1·mM−1) | ||||||
|---|---|---|---|---|---|---|---|---|
| Peptide | Sequence | EGF… | − | + | − | + | − | + |
| EGFR-Y845 | LLGAEEKEYHAEGGKVP | 931±56 | 943±42 | 1.4±0.1 | 5.6±0.1 | 1.5±0.1 | 5.9±0.7 | |
| EGFR-Y845/K843Q | LLGAEEQEYHAEGGKVP | 266±18 | 213±10 | 2.1±0.1 | 11.2±0.2 | 7.1±0.9 | 52.6±3.6 | |
| ErbB4-Y1221 | ANTLGKAEYLKNNILSM | 1805±365 | 1567±198 | 1.4±0.2 | 8.1±0.3 | 0.8±0.4 | 5.2±0.7 | |
| ErbB4-Y1221/K1218Q | ANTLGQAEYLKNNILSM | 567±63 | 521±40 | 1.8±0.2 | 11.3±0.3 | 3.2±0.2 | 21.7±1.0 | |