TABLE 2.
Kinetic parameters for the K. pneumoniae recombinant TyrATa
| Substrate | Cosubstrate | Apparent Km (mM) | Apparent Vmax (μmol/min/mg) |
|---|---|---|---|
| Tyrosine | 10 mM KMTB | 2.01 ± 0.13 | 3.25 ± 0.09 |
| Phenylalanine | 10 mM KMTB | 2.01 ± 0.46 | 1.80 ± 0.14 |
| Tryptophan | 10 mM KMTB | 1.42 ± 0.20 | 2.63 ± 0.11 |
| Glutamate | 10 mM KMTB | 11.93 ± 0.75 | 7.65 ± 0.29 |
| KMTB | 5 mM tyrosine | 2.46 ± 0.27 | 3.29 ± 0.13 |
| α-Ketoglutarate | 5 mM tyrosine | 3.00 ± 0.24 | 5.21 ± 0.15 |
| Oxaloacetate | 5 mM tyrosine | 6.00 ± 0.91 | 7.39 ± 0.52 |
| Pyruvate | 5 mM tyrosine | 20.13 ± 8.21 | 0.09 ± 0.03 |
a
Amino acid production was determined by incubations of mixtures containing 10 mM phosphate buffer (pH 7.4), 50 μM pyridoxal phosphate, cosubstrate (at the indicated concentration), and 0.01 to 10 mM substrate and subsequent HPLC analysis as described in Materials and Methods. Kinetic values were determined by nonlinear least-squares fitting to the Michaelis-Menton equation by using the Scientist software package (MicroMath, Salt Lake City, Utah) and are shown with the standard deviations.