Table 6.
Kinetic parameters of L-phenylalanine transport.
| Strains | Medium | K T1 (μM) | J max1 | K T2 (mM) | J max2 | NS |
|---|---|---|---|---|---|---|
| Y294 | MP | 11 ± 2 | 0.85 ± 0.02 | 0.77 ± 0.3 | 0.46 ± 0.05 | 0.42 ± 0.02 |
| MA | 24 ± 5 67 ± 26 |
0.86 ± 0.08 0.21 ± 0.07 |
— | |||
|
| ||||||
| Y294Δbap2 | MP | 4.7 ± 1 | 0.58 ± 0.03 | — | — | 0.46 ± 0.02 |
| MA | 67 ± 26 | 0.21 ± 0.07 | 0.77 ± 0.3 | 0.46 ± 0.05 | — | |
|
| ||||||
| Y294Δagp1 | MP | 11 ± 1 | 1.04 ± 0.04 | — | — | 0.47 ± 0.03 |
| MA | 26 ± 2 | 1.37 ± 0.02 | — | — | — | |
|
| ||||||
| Y294Δgap1 | MP | — | — | 0.75 ± 0.3 | 14.3 ± 2.0 | 2.97 ± 1.10 |
| MA | 39 | 0.34 | 0.70 | 5.09 | 2.66 | |
|
| ||||||
| Y294Δagp1Δgap1 | MP | — | — | — | — | 2.91 |
| MA | 39 | 0.6 | — | — | 2.55 | |
L-[14C]-phenylalanine uptake was assayed as described in Section 2. Uptake data were plotted as Michaelis-Menten and Lineweaver-Burk plots (data not shown) and the kinetic parameters estimated using the Solver program of Microsoft Excel.
NS: nonspecific (K T ≥ 1 M).