Characterization of the quinone reductase activity of the ferric reductase B protein from Paracoccus denitrificans

2009 ◽  
Vol 483 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Vojtěch Sedláček ◽  
Rob J.M. van Spanning ◽  
Igor Kučera
Keyword(s):  
Paracoccus Denitrificans ◽  
Reductase Activity ◽  
Quinone Reductase ◽  
Ferric Reductase

Sulfide-quinone reductase activity in membranes of the chemotrophic bacterium Paracoccus denitrificans GB17

1998 ◽  
Vol 170 (5) ◽  
pp. 353-360 ◽  
Author(s):  
M. Schütz ◽  
Christof Klughammer ◽  
Christoph Griesbeck ◽  
Armin Quentmeier ◽  
Cornelius G. Friedrich ◽  
...  
Keyword(s):  
Paracoccus Denitrificans ◽  
Reductase Activity ◽  
Quinone Reductase

Purification and characterization of an azoreductase from Escherichia coli CD-2 possessing quinone reductase activity

2012 ◽  
Vol 47 (3) ◽  
pp. 544-549 ◽  
Author(s):  
Daizong Cui ◽  
Guofang Li ◽  
Dan Zhao ◽  
Xiaoxu Gu ◽  
Chunlei Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Reductase Activity ◽  
Quinone Reductase ◽  
Purification And Characterization

scholarly journals Genetic and Physiologic Characterization of Ferric/Cupric Reductase Constitutive Mutants ofCryptococcus neoformans

1999 ◽  
Vol 67 (5) ◽  
pp. 2357-2365 ◽  
Author(s):  
Karin J. Nyhus ◽  
Eric S. Jacobson
Keyword(s):  
Hydrogen Peroxide ◽  
Iron Uptake ◽  
Reductase Activity ◽  
Iron Acquisition ◽  
Uptake System ◽  
Ferric Reductase ◽  
Pathogenic Yeast ◽  
Oxidative Stresses ◽  
Mutant Strains

ABSTRACT Cryptococcus neoformans is a pathogenic yeast that causes meningitis in immunocompromised patients. Because iron acquisition is critical for growth of a pathogen in a host, we studied the regulation of the ferric reductase and ferrous uptake system of this organism. We isolated 18 mutants, representing four independent loci, with dysregulated ferric reductase. The mutant strains had >10-fold higher than wild-type WT reductase activity in the presence of iron. Two of the strains also had >7-fold higher than WT iron uptake in the presence of iron but were not markedly iron sensitive. Both were sensitive to the oxidative stresses associated with superoxide and hydrogen peroxide. One strain exhibited only 23% of the WT level of iron uptake in the absence of iron and grew poorly without iron supplementation of the medium, phenotypes consistent with an iron transport deficiency; it was sensitive to superoxide but not to hydrogen peroxide. The fourth strain had high reductase activity but normal iron uptake; it was not very sensitive to oxidative stress. We also demonstrated that the ferric reductase was regulated by copper and could act as a cupric reductase. Sensitivity to oxidants may be related to iron acquisition by a variety of mechanisms and may model the interaction of the yeast with the immune system.

scholarly journals Svalbamides A and B, Pyrrolidinone-Bearing Lipodipeptides from Arctic Paenibacillus sp.

Marine Drugs ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. 229
Author(s):  
Young Eun Du ◽  
Eun Seo Bae ◽  
Yeonjung Lim ◽  
Jang-Cheon Cho ◽  
Sang-Jip Nam ◽  
...  
Keyword(s):  
Reductase Activity ◽  
Quinone Reductase ◽  
The Arctic ◽  
Amino Acid Residues ◽  
Chemopreventive Agents ◽  
Svalbard Archipelago ◽  
Paenibacillus Sp ◽  
Combinational Analysis ◽  
Culture Extract ◽  
The Absolute

Two new secondary metabolites, svalbamides A (1) and B (2), were isolated from a culture extract of Paenibacillus sp. SVB7 that was isolated from surface sediment from a core (HH17-1085) taken in the Svalbard archipelago in the Arctic Ocean. The combinational analysis of HR-MS and NMR spectroscopic data revealed the structures of 1 and 2 as being lipopeptides bearing 3-amino-2-pyrrolidinone, d-valine, and 3-hydroxy-8-methyldecanoic acid. The absolute configurations of the amino acid residues in svalbamides A and B were determined using the advanced Marfey’s method, in which the hydrolysates of 1 and 2 were derivatized with l- and d- forms of 1-fluoro-2,4-dinitrophenyl-5-alanine amide (FDAA). The absolute configurations of 1 and 2 were completely assigned by deducing the stereochemistry of 3-hydroxy-8-methyldecanoic acid based on DP4 calculations. Svalbamides A and B induced quinone reductase activity in Hepa1c1c7 murine hepatoma cells, indicating that they represent chemotypes with a potential for functioning as chemopreventive agents.

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