Kinetic parameters of the wild-type and R510Q mutant erythrocyte pyruvate kinases
| . | PEP* . | ADP† . | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| FBP (−) . | 1 mM FBP . | ||||||||||
| kcat (s−1) . | S0.5 (mM) . | nH . | kcat/S0.5(s−1/mM) . | kcat (s−1) . | S0.5 (mM) . | nH . | kcat/S0.5(s−1/mM) . | kcat (s−1) . | Km (mM) . | kcat/Km(s−1/mM) . | |
| Wild-type | 355 ± 12 | 1.1 ± 0.04 | 1.60 ± 0.16 | 323 | 355 ± 11 | 0.18 ± 0.02 | 1.05 ± 0.07 | 1972 | 355 ± 13 | 0.17 ± 0.01 | 2088 |
| R510Q | 340 ± 10 | 1.6 ± 0.11 | 1.75 ± 0.19 | 212 | 304 ± 12 | 0.31 ± 0.02 | 1.08 ± 0.08 | 980 | 351 ± 10 | 0.24 ± 0.02 | 1463 |
| . | PEP* . | ADP† . | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| FBP (−) . | 1 mM FBP . | ||||||||||
| kcat (s−1) . | S0.5 (mM) . | nH . | kcat/S0.5(s−1/mM) . | kcat (s−1) . | S0.5 (mM) . | nH . | kcat/S0.5(s−1/mM) . | kcat (s−1) . | Km (mM) . | kcat/Km(s−1/mM) . | |
| Wild-type | 355 ± 12 | 1.1 ± 0.04 | 1.60 ± 0.16 | 323 | 355 ± 11 | 0.18 ± 0.02 | 1.05 ± 0.07 | 1972 | 355 ± 13 | 0.17 ± 0.01 | 2088 |
| R510Q | 340 ± 10 | 1.6 ± 0.11 | 1.75 ± 0.19 | 212 | 304 ± 12 | 0.31 ± 0.02 | 1.08 ± 0.08 | 980 | 351 ± 10 | 0.24 ± 0.02 | 1463 |
Results are means (SE) for 3 determinations from 4 different protein preparations. PEP, phosphoenolpyruvate; FBP, fructose 1,6-bisphosphate; ADP, adenosine diphosphate.
Kinetic parameters for PEP were obtained at fixed 1.5 mM ADP by fitting data to the Hill plot.
Kinetic parameters for ADP were obtained at fixed 5 mM PEP by fitting data to the Lineweaver-Burk plot.