Table 1. Kinetic properties of aroA_{J. sp} and aroA_{E. coli}^a.

Enzyme	Sp act (nKat/mg)	Km(PEP)b (μM)	Km(S3P)b (μM)	Ki c (μM)	IC50d (mM)	Ki/Km(PEP)
AroAJ. sp	27.9 ± 3	30 ± 4	83 ± 11	373 ± 50	3.6 ± 0.2	12.4
AroAE. coli	15.6 ± 4	60 ± 7	115 ± 10	0.9 ± 0.09	0.04 ± 0.01	0.015

^aThe results are the averages of two sets of experiments conducted in triplicate.

^bThe PEP or S3P concentration was set at 0.05, 0.067, 0.1, 0.2, 0.5, and 1 mM, while the concentration of the other one was fixed at 1.0 mM.

^cCompetitive inhibition by glyphosate with respect to PEP was demonstrated by lines converging on the x axes of Lineweaver-Burk plots. The PEP concentration was set at 0.067, 0.1, 0.2, and 0.5 mM, respectively, while the glyphosate concentration was 0, 5, 10, 20, and 50 μM in determining the inhibition of aroA_{E. coli}; and the glyphosate concentration was 0, 0.1, 0.5, 1, 2 and 5 mM in determining the inhibition of aroA_{J. sp}. S3P concentration was fixed at 1 mM.

^dThe glyphosate concentration causing 50% inhibition of enzyme activity, which was determined by fitting the data to the equation: V = V min + (V max −V min)/(1 + ([I]/IC 50)ⁿ), and V was determined at 1 mM PEP and 1 mM S3P with the glyphosate concentration ranging from 0.0001 mM to 100 mM.