Table 3. Steady-state kinetic constants of EGFR tyrosine kinase with peptide substrates derived from ErbB4.
Results represent means±S.E.M.
| Km (μM) | kcat (min−1) | kcat/Km (min−1·mM−1) | ||||||
|---|---|---|---|---|---|---|---|---|
| ErbB3 tyrosine position | Sequence | EGF… | − | + | − | + | − | + |
| 1022 | EDMMDAEEYLVPQAFNI | 279±13 | 260±20 | 3.1±0.1 | 17.0±0.4 | 11.1±0.9 | 65.3±7.4 | |
| 1056 | IGHSPPPAYTPMSGNQF | 1072±120 | 1752±234 | 0.7±0.1 | 3.0±0.2 | 0.7±0.1 | 1.7±0.4 | |
| 1150 | RGELDEEGYMTPMRDKP | 865±44 | 579±32 | 4.1±0.1 | 15.5±0.4 | 4.7±0.4 | 26.8±2.3 | |
| 1162 | MRDKPKQEYLNPVEENP | 1100±154 | 1093±81 | 2.0±0.1 | 12.5±0.5 | 1.9±0.4 | 11.4±1.4 | |
| 1188 | LQALDNPEYHNASNGPP | 291±23 | 286±16 | 2.4±0.2 | 15.3±0.3 | 8.2±0.9 | 53.5±3.0 | |
| 1202 | ASNGPPKAEDEYVNEPL | 284±19 | 194±10 | 2.9±0.1 | 14.8±0.2 | 10.1±1.1 | 76.3±4.9 | |
| 1221 | ANTLGKAEYLKNNILSM | 1805±365 | 1567±198 | 1.4±0.2 | 8.1±0.3 | 0.8±0.4 | 5.2±0.7 | |
| 1242 | KKAFDNPDYWNHSLPPR | 276±18 | 172±16 | 4.4±0.2 | 21.1±0.6 | 15.9±2.0 | 122.7±3.4 | |
| 1258 | HSLPPRSTLQHPDYLQE | 377±19 | 271±14 | 3.5±0.2 | 19.5±0.3 | 9.3±0.1 | 72.0±2.8 | |
| 1284 | PIVAENPEYLSEFSLKP | 335±36 | 287±25 | 2.7±0.1 | 15.7±0.3 | 8.1±0.8 | 54.7±4.6 | |