Inhibitory Effects of Galloylglucose on Nicotinamide Adenine Dinucleotide Dehydrogenases of the Aerobic Respiratory Chain of Escherichia coli

The effects of pentagalloylglucose (1, 2, 3, 4, 6-penta-O-galloyl-β-D-glucose) on the aerobic electron transport system of Escherichia coli were studied. The activity of nicotineamide adenine dinucleotide (NADH) reductase was inhibited by pentagalloylglucose, but the activities of succinate dehydrogenase, D-lactate dehydrogenase, and ubiquinol-1 (Q1H2) oxidase were not susceptible to the inhibitor. Because the presence of two kinds of NADH dehydrogenase in respiratory chain of "Escherichia coli has been reported, we examined the effect of galloylglucose independently on both NADH dehydrogenases.Pentagalloylglucose is potent and specific inhibitor of both NADH dehydrogenases. One of the NADH dehydrogenases (NADH dh II) is more sensitive to the inhibitor than the other (NADH dh I).