Table 2. Steady-state kinetic constants of EGFR tyrosine kinase with peptide substrates derived from ErbB3.
Results represent means±S.E.M.
| Km (μM) | kcat (min−1) | kcat/Km (min−1·mM−1) | ||||||
|---|---|---|---|---|---|---|---|---|
| ErbB3 tyrosine position | Sequence | EGF… | − | + | − | + | − | + |
| 1035 | SLLSPSSGYMPMNQGNL | 528±91 | 841±87 | 0.1±0.1 | 0.5±0.1 | 0.2±0.1 | 0.6±0.1 | |
| 1140 | LEEEDVNGYVMPDTHLK | 152±15 | 176±13 | 2.5±0.1 | 16.2±0.4 | 16.1±2.7 | 92.1±10 | |
| 1178/1180 | EEEDEDEEYEYMNRRRR | 129±10 | 114±8 | 3.0±0.1 | 14.5±0.3 | 23.1±2.6 | 128±12 | |
| 1203/1205 | PSSLEELGYEYMDVGSD | 111±11 | 153±10 | 3.1±0.1 | 15.8±0.3 | 28.3±3.5 | 103±9 | |
| 1241/1243 | AGTTPDEDYEYMNRQRD | 118±13 | 109±6 | 3.2±0.1 | 19.4±0.3 | 27.5±3.9 | 179±13 | |
| 1257 | DGGGPGGDYAAMGACPA | 343±29 | 460±20 | 1.4±0.1 | 9.2±0.4 | 4.1±0.7 | 20.0±1.8 | |
| 1270 | ACPASEQGYEEMRAFQG | 931±99 | 836±64 | 1.2±0.1 | 7.6±0.3 | 1.3±0.23 | 9.1±1.1 | |
| 1309 | DSAFDNPDYWHSRLFPK | 245±16 | 232±10 | 2.8±0.1 | 15.7±0.2 | 11.3±1.1 | 67.8±4.0 | |