Table 3. Substrate dependent GS activity (kcat)a.
Enzyme | GAB + Gly + ATP | GAB + ATP | % Gly Independent |
---|---|---|---|
Wild-type | 18.83 ± 0.77 | 0 | 0 |
G369V | 0.133 ± 0.001 | 0.114 ± 0.017 | 85 |
G370V | 0.052 ± 0.026 | 0.057 ± 0.024 | 100 |
G371V | 2.36 ± 0.35 | 0.116 ± 0.065 | 5 |
Results are averages of replicate assays of two or three different enzyme preparations. For these studies the background rate subtracted to obtain Kcat values is that of ATP-Mg alone (Enzyme+ATP-Mg). There is no activity with glycine plus ATP.