scholarly journals Identification of the NADH-oxidase gene in Trichomonas vaginalis

2019 ◽  
Vol 119 (2) ◽  
pp. 683-686 ◽  
Author(s):  
Aline Lamien-Meda ◽  
David Leitsch
Keyword(s):  
Oxidase Activity ◽  
Trichomonas Vaginalis ◽  
Nadh Oxidase ◽  
Flavin Mononucleotide ◽  
Flavin Reductase ◽  
Oxidase Gene ◽  
Reading Frame ◽  
Sexually Transmitted ◽  
Cell Extracts ◽  
Nadh Oxidase Activity

AbstractThe microaerophilic human parasite Trichomonas vaginalis causes infections in the urogenital tract and is one of the most often sexually transmitted pathogens worldwide. Due to its anaerobic metabolism, it has to quickly remove intracellular oxygen in order to avoid deactivation of essential metabolic enzymes such as oxygen-sensitive pyruvate:ferredoxin oxidoreductase (PFOR). Two major enzyme activities which are responsible for the removal, i.e. reduction, of molecular oxygen have been identified in T. vaginalis flavin reductase, formerly designated NADPH oxidase, which indirectly reduces oxygen to hydrogen peroxide via flavin mononucleotide (FMN), and NADH oxidase which reduces oxygen to water. Flavin reductase has been identified and characterized at the gene level as well as enzymatically, but NADH oxidase has so far only been characterized enzymatically with enzyme isolated from T. vaginalis cell extracts. In this study, we identified NADH oxidase by mass spectrometry after isolation of the enzyme from gel bands positively staining for NADH oxidase activity. In strain C1 (ATCC 30001) which is known to lack NADH oxidase activity completely, the NADH oxidase gene has a deletion at position 1540 of the open reading frame leading to a frame shift and, as a consequence, to premature termination of the encoded polypeptide.

scholarly journals Gene Cloning and Molecular Characterization of a Two-Enzyme System Catalyzing the Oxidative Detoxification of β-Endosulfan

2002 ◽  
Vol 68 (12) ◽  
pp. 6237-6245 ◽  
Author(s):  
Tara D. Sutherland ◽  
Irene Horne ◽  
Robyn J. Russell ◽  
John G. Oakeshott
Keyword(s):  
Shuttle Vector ◽  
Open Reading Frame ◽  
Cosmid Library ◽  
Flavin Mononucleotide ◽  
Flavin Reductase ◽  
Reading Frame ◽  
Reductase Gene ◽  
Degradation Activity ◽  
Layer Chromatography

ABSTRACT The gram-positive bacterium Mycobacterium sp. strain ESD is able to use the cyclodiene insecticide endosulfan as a source of sulfur for growth. This activity is dependent on the absence of sulfite or sulfate in the growth medium. A cosmid library of strain ESD DNA was constructed in a Mycobacterium-Escherichia coli shuttle vector and screened for endosulfan-degrading activity in Mycobacterium smegmatis, a species that does not degrade endosulfan. Using this method, we identified a single cosmid that conferred sulfur-dependent endosulfan-degrading activity on the host strain. An open reading frame (esd) was identified within this cosmid that, when expressed behind a constitutive promoter in a mycobacterial expression vector, conferred sulfite- and sulfate-independent β-endosulfan degradation activity on the recombinant strain. The translation product of this gene (Esd) had up to 50% sequence identity with an unusual family of monooxygenase enzymes that use reduced flavins, provided by a separate flavin reductase enzyme, as cosubstrates. An additional partial open reading frame was located upstream of the Esd gene that had sequence homology to the same monooxygenase family. A flavin reductase gene, identified in the M. smegmatis genome, was cloned, expressed, and used to provide reduced flavin mononucleotide for Esd in enzyme assays. Thin-layer chromatography and gas chromatography analyses of the enzyme assay mixtures revealed the disappearance of β-endosulfan and the appearance of the endosulfan metabolites, endosulfan monoaldehyde and endosulfan hydroxyether. This suggests that Esd catalyzes the oxygenation of β-endosulfan to endosulfan monoaldehyde and endosulfan hydroxyether. Esd did not degrade either α-endosulfan or the metabolite of endosulfan, endosulfan sulfate.

scholarly journals NADH Oxidase Activity of Mitochondrial Apoptosis-inducing Factor

2001 ◽  
Vol 276 (19) ◽  
pp. 16391-16398 ◽  
Author(s):  
M. Dolores Miramar ◽  
Paola Costantini ◽  
Luigi Ravagnan ◽  
Ligia M. Saraiva ◽  
Delphine Haouzi ◽  
...  
Keyword(s):  
Oxidase Activity ◽  
Nadh Oxidase ◽  
Mitochondrial Apoptosis ◽  
Nadh Oxidase Activity ◽  
Apoptosis Inducing Factor

Effects of Vanadate on the Molybdoproteins Xanthine Oxidase and Nitrate Reductase: Kinetic Evidence for Multiple Site Interaction

1980 ◽  
Vol 35 (9-10) ◽  
pp. 702-707 ◽  
Author(s):  
Candadai S. Ramadoss
Keyword(s):  
Catalytic Activity ◽  
Nitrate Reductase ◽  
Xanthine Oxidase ◽  
Oxidase Activity ◽  
Metal Ion ◽  
Nadh Oxidase ◽  
Multiple Site ◽  
Vanadate Inhibition ◽  
Nadh Oxidase Activity

Abstract The inhibition of the activity of xanthine oxidase by vanadate was strikingly similar to vanadate inhibition of another molybdoprotein nitrate reductase. Although the main catalytic activity of both enzymes was inhibited, the partial NADH oxidase activity associated with these enzymes was stimulated several fold. It appears that the metal ion binds at multiple site in both enzymes. In the absence of any enzymes a combination of vanadium (V) and molybdenum (V) in air was found to oxide NADH rapidly.

scholarly journals Blockade of endogenous tissue kallikrein aggravates renal injury by enhancing oxidative stress and inhibiting matrix degradation

2010 ◽  
Vol 298 (4) ◽  
pp. F1033-F1040 ◽  
Author(s):  
Yuying Liu ◽  
Grant Bledsoe ◽  
Makato Hagiwara ◽  
Zhi-Rong Yang ◽  
Bo Shen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidase Activity ◽  
Nadh Oxidase ◽  
Ischemia Reperfusion ◽  
Matrix Metalloproteinase 2 ◽  
Intercellular Adhesion Molecule ◽  
Tissue Kallikrein ◽  
Matrix Degradation ◽  
Nadh Oxidase Activity ◽  
Pai 1

Levels of tissue kallikrein (TK) are significantly lower in the urine of patients with kidney failure, and TK expression is specifically diminished in rat kidney after recovery from ischemia-reperfusion injury. In this study, we investigated the functional consequence of blocking endogenous TK activity in a rat model of chronic kidney disease. Inhibition of endogenous TK levels for 10 days by neutralizing TK antibody injection in DOCA-salt rats caused a significant increase in blood urea nitrogen and urinary protein levels, and a decrease in creatinine clearance. Kidney sections from anti-TK antibody-treated rats displayed a marked rise in tubular dilation and protein cast accumulation as well as glomerular sclerosis and size. TK blockade also increased inflammatory cell infiltration, myofibroblast and collagen accumulation, and collagen fraction volume. Elevated renal inflammation and fibrosis by anti-TK antibody were associated with increased expression of tumor necrosis factor-α, intercellular adhesion molecule-1, tissue inhibitor of metalloproteinase-2 (TIMP-2), and plasminogen activator inhibitor-1 (PAI-1). Moreover, the detrimental effect of TK blockade resulted in reduced nitric oxide (NO) levels as well as increased serum lipid peroxidation, renal NADH oxidase activity, and superoxide formation. In cultured proximal tubular cells, TK inhibited angiotensin II-induced superoxide production and NADH oxidase activity via NO formation. In addition, TK markedly increased matrix metalloproteinase-2 activity with a parallel reduction of TIMP-2 and PAI-1 synthesis. These findings indicate that endogenous TK has the propensity to preserve kidney structure and function in rats with chronic renal disease by inhibiting oxidative stress and activating matrix degradation pathways.

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