Here, we report for the first time that the Streptococcus sanguinis nox gene encoding NADH oxidase is involved in both competition with Streptococcus mutans and virulence for infective endocarditis. An S. sanguinis nox mutant was found to fail to inhibit the growth of Streptococcus mutans under microaerobic conditions. In the presence of oxygen, the recombinant Nox protein of S. sanguinis could...

The formation of hydrogen peroxide during the oxidation of NADH by purified preparations of cytochrome o has been demonstrated by employing three independent methods: polarographic, calorimetric, and fluorometric. The first two methods were used to assay for the accumulation of hydrogen peroxide and showed that hydrogen peroxide did accumulate as a product, but only about 30% of the oxygen cons...

The formation of hydrogen peroxide during the oxidation of NADH by purified preparations of cytochrome o has been demonstrated by employing three independent methods: polarographic, colorimetric, and fluorometric. The first two methods were used to assay for the accumulation of hydrogen peroxide and showed that hydrogen peroxide did accumulate as a product, but only about 30% of the oxygen cons...

The formation of hydrogen peroxide during the oxidation of NADH by purified preparations of cytochrome o has been demonstrated by employing three independent methods: polarographic, calorimetric, and fluorometric. The first two methods were used to assay for the accumulation of hydrogen peroxide and showed that hydrogen peroxide did accumulate as a product, but only about 30% of the oxygen cons...

Xanthine Oxidase is of importance because of its potential to generate superoxide anion and hydrogen peroxide; reactive oxygen species that have been implicated in many instances of ischaemia-reperfusion injury [I]. The proposed pathogenic mechanism (21 is largely based on the well known properties of the bovine milk and rat liver enzymes [3] and depends on the ischaemia-induced proteolytic con...

We have previously reported that inhibition of Cu/Zn superoxide dismutase (SOD) in endothelium-removed bovine pulmonary arteries (BPA) attenuates nitrovasodilator-elicited relaxation and that a NADH oxidase linked to the redox status of cytosolic NADH is the major detectable source of superoxide ([Formula: see text]) production in this tissue. In the present study, we investigated whether NADH ...

Myocardial ischemia-reperfusion is associated with bursts of reactive oxygen species (ROS) such as superoxide radicals (O(2)(-).). Membrane-associated NADH oxidase (NADHox) activity is a hypothetical source of O(2)(-)., implying the NADH concentration-to-NAD(+) concentration ratio ([NADH]/[NAD(+)]) as a determinant of ROS. To test this hypothesis, cardiac NADHox and ROS formation were measured ...

The purified respiratory chain NADH dehydrogenase of Escherichia coli oxidizes NADH with either dichlorophenolindophenol (DCIP). ferricyanide, or menadione as electron acceptors, with values for NADH are similar with the three electron acceptors (approximately 50 muM). The purified enzyme contains no flavin and has an absolute requirement for FAD, with Km values around 4 muM. The pH optimum of ...

The activity of an auxin-stimulated NADH oxidase of the plasma membrane of hypocotyls of etiolated soybean (Glycine max Merr.) seedlings responded to guanine and other nucleotides, but in a manner that differed from that of enzymes coupled to the classic trimeric and low molecular weight monomeric guanine nucleotide-binding proteins (G proteins). In the presence and absence of either auxin or d...