Figure 3 | Scientific Reports

Figure 3

From: Triazolopyrimidine herbicides are potent inhibitors of Aspergillus fumigatus acetohydroxyacid synthase and potential antifungal drug leads

Figure 3

Inhibition of AfuAHAS by commercial herbicides. (a) Measurement of AfuAHAS activity in the presence and absence of 0.5 µM CE to determine herbicide binding stoichiometry. Extrapolation of the linear regression line (dashed line) showed that 1.06 µM of enzyme was fully inhibited by 0.5 µM CE. (b) AfuAHAS catalytic activity vs. inhibitor concentration. The data were fitted using Eq. (1) (see “Materials and methods”) for tight binding inhibitors. (c) Correlation of Ki values between AfuAHAS and CaAHAS for the five AHAS herbicide families. TP: Triazolopyrimidines, SU: Sulfonylureas, SCT: Sulfonylamino-carbonyl-triazolinones, PB: Pyrimidinyl-benzoates, IMI: Imidazolinones. d. Accumulative inhibition curves for PS, MT and CE. The data were fitted using Eq. (3) (dashed line). For a direct comparison of the strength of accumulative inhibition, the F value (free enzyme/enzyme-inhibitor complex ratio) was set to 105 for the three inhibitors. The data show that MT is the most potent accumulative inhibitor. Images were created using GraphPad Prism 7.01.

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