TABLE 2.
Enzyme | Values for indicated substrate
|
Residual activity in the presence of 10 mM inhibitor(s) (%)a
|
||||||
---|---|---|---|---|---|---|---|---|
Pyruvate + pyruvate
|
α-Ketobutyrate + pyruvate
|
|||||||
Km,P (mM) | Vmax,P (mU/mg) | Km,K (mM) | Vmax,K (mU/mg) | l-Valine | l-Isoleucine | l-Leucine | All three BCAAs | |
Wild-type AHAS | 7.8 | 77.6 | 5.6 | 113.9 | 50 | 54 | 65 | 46 |
AHAS ΔC-T ilvN | 4.7 | 22.3 | 6.9 | 56.8 | 104 | 104 | 104 | 107 |
Activities were measured using 50 mM pyruvate as the substrate. A value of 100% corresponds to 73.5 mU/mg for the WT AHAS and 22.1 mU/mg for AHAS ΔC-T ilvN.