The role of a novel cytochrome b-costaining nitrate reductase and quinone in the invitro reconstruction of formate-nitrate reductase activity of E. coli.

1974 ◽  
Vol 61 (4) ◽  
pp. 1234-1241 ◽  
Author(s):  
H.G. Enoch ◽  
R.L. Lester
Keyword(s):  
Nitrate Reductase ◽  
Cytochrome B ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
E Coli

scholarly journals Differential regulatory role of nitric oxide in mediating nitrate reductase activity in roots of tomato (Solanum lycocarpum)

2009 ◽  
Vol 104 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Chong Wei Jin ◽  
Shao Ting Du ◽  
Yong Song Zhang ◽  
Xian Yong Lin ◽  
Cai Xian Tang
Keyword(s):  
Nitric Oxide ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Regulatory Role

scholarly journals Salivary Nitrate, Nitrite and Nitrate Reductase Activity in Relation to Risk of Oral Cancer in Egypt

1998 ◽  
Vol 14 (2) ◽  
pp. 91-97 ◽  
Author(s):  
Alaa F. Badawi ◽  
Gehan Hosny ◽  
Mohamed El-Hadary ◽  
Mostafa H. Mostafa
Keyword(s):  
Oral Cancer ◽  
Nitrate Reductase ◽  
Odds Ratio ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Healthy Individuals ◽  
Oral Cancer Patients ◽  
Nitrate And Nitrite ◽  
Increased Activity

It has been suggested that nitrate and nitrite may play a role in the etiology of human oral cancer. We investigated whether salivary nitrate and nitrite and the activity of nitrate reductase (NRase) may affect the risk of oral cancer in Egypt, an area with high levels of environmental nitrosating agents. Levels of salivary nitrite (8.3 ± 1.0 μg/ml) and nitrate (44 ± 3.7 μg/ml) and activity of NRase (74 ± 10 nmol/ml/min) were significantly (P< 0.05) higher in oral cancer patients (n= 42) compared to control Egyptian healthy individuals (n= 40, nitrite = 5.3 ± 0.3 μg/ml, nitrate = 27 ± 1.2 μg/ml, and NRase activity = 46 ± 4 nmol/ml/min). The adjusted odds ratio (OR) and the 95% confidence intervals (C.I.) for risk of oral cancer, categorized by the levels of salivary nitrate and nitrite and NRase activity, showed a higher cancer risk associated with nitrite > 7.5 μg/ml (OR: 3.0, C.I.: 1.0–9.3), nitrite > 40 μg/ml (OR: 4.3, C.I.: 1.4–13.3) and NRase activity > 50 nmol/ml/min (OR: 2.9, C.I.: 1.1–7.4). Our findings suggest that increased consumption of dietary nitrate and nitrite is associated with elevated levels of salivary nitrite. Together with the increased activity of salivary NRase, these observations may explain, at least in part, the role of nitrate and nitrite in the development of oral cancer in individuals from an area with a high burden ofN-nitroso precursors.

A Study on the Etiological Factors of Bilharzial Bladder Cancer in Egypt. 6. The Possible Role of Urinary Bacteria

1982 ◽  
Vol 68 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Abdelbaset Anwer El-Aaser ◽  
Mahmoud Mohamed El-Merzabani ◽  
Nadia Ahmed Higgy ◽  
Abdel E. El-Habet
Keyword(s):  
Escherichia Coli ◽  
Bladder Cancer ◽  
Enzyme Activity ◽  
Nitrate Reductase ◽  
Bacterial Infection ◽  
Schistosoma Haematobium ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Glucuronidase Activity

A correlation was obtained between a positive nitrite test in urine and the severity of urinary bacterial infection. Bacteria isolated from the urine of bilharzial or bladder cancer patients were found to be rich in nitrate reductase activity. « Escherichia coli » was the most common microorganism isolated from these specimens. Urine and several urinary constituents activate bacterial nitrate reductase. β-Glucuronidase activity in the urine of patients with chronic « Schistosoma haematobium » infection and bladder cancer was measured and shown to be significantly greater than that of urine of normal control subjects. Urinary bacterial infection was shown to be the source of the increased urinary level of enzyme activity at pH 7.0.

Nitrate reductase activity in Paul's scarlet rose suspension cultures and the differential role of nitrate and molybdenum in induction

Planta ◽  
1978 ◽  
Vol 141 (2) ◽  
pp. 183-189 ◽  
Author(s):  
R. W. Jones ◽  
A. J. Abbott ◽  
E. J. Hewitt ◽  
G. R. Best ◽  
E. F. Watson
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Suspension Cultures

scholarly journals Periplasmic Nitrate Reductase (NapABC Enzyme) Supports Anaerobic Respiration by Escherichia coli K-12

2002 ◽  
Vol 184 (5) ◽  
pp. 1314-1323 ◽  
Author(s):  
Valley Stewart ◽  
Yiran Lu ◽  
Andrew J. Darwin
Keyword(s):  
Escherichia Coli ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Anaerobic Respiration ◽  
Null Alleles ◽  
E Coli ◽  
Periplasmic Nitrate Reductase ◽  
Nitrate Concentrations ◽  
K 12

ABSTRACT Periplasmic nitrate reductase (NapABC enzyme) has been characterized from a variety of proteobacteria, especially Paracoccus pantotrophus. Whole-genome sequencing of Escherichia coli revealed the structural genes napFDAGHBC, which encode NapABC enzyme and associated electron transfer components. E. coli also expresses two membrane-bound proton-translocating nitrate reductases, encoded by the narGHJI and narZYWV operons. We measured reduced viologen-dependent nitrate reductase activity in a series of strains with combinations of nar and nap null alleles. The napF operon-encoded nitrate reductase activity was not sensitive to azide, as shown previously for the P. pantotrophus NapA enzyme. A strain carrying null alleles of narG and narZ grew exponentially on glycerol with nitrate as the respiratory oxidant (anaerobic respiration), whereas a strain also carrying a null allele of napA did not. By contrast, the presence of napA+ had no influence on the more rapid growth of narG+ strains. These results indicate that periplasmic nitrate reductase, like fumarate reductase, can function in anaerobic respiration but does not constitute a site for generating proton motive force. The time course of Φ(napF-lacZ) expression during growth in batch culture displayed a complex pattern in response to the dynamic nitrate/nitrite ratio. Our results are consistent with the observation that Φ(napF-lacZ) is expressed preferentially at relatively low nitrate concentrations in continuous cultures (H. Wang, C.-P. Tseng, and R. P. Gunsalus, J. Bacteriol. 181:5303-5308, 1999). This finding and other considerations support the hypothesis that NapABC enzyme may function in E. coli when low nitrate concentrations limit the bioenergetic efficiency of nitrate respiration via NarGHI enzyme.

Role of light and CO2 fixation in the control of nitrate-reductase activity in barley leaves

Planta ◽  
1993 ◽  
Vol 190 (2) ◽  
pp. 277-283 ◽  
Author(s):  
Alfonso de Cires ◽  
Angel de la Torre ◽  
Begoña Delgado ◽  
Catalina Lara
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Co2 Fixation ◽  
Reductase Activity ◽  
Barley Leaves ◽  
Role Of Light
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