Extracellular iron reductase activity produced by Listeria monocytogenes

1996 ◽  
Vol 166 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Esau Barchini ◽  
Richard E. Cowart
Keyword(s):  
Listeria Monocytogenes ◽  
Reductase Activity ◽  
Iron Reductase

scholarly journals Microevolution During Serial Mouse Passage Demonstrates FRE3 as a Virulence Adaptation Gene in Cryptococcus neoformans

mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Guowu Hu ◽  
Shu Hui Chen ◽  
Jin Qiu ◽  
John E. Bennett ◽  
Timothy G. Myers ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Transcriptome Sequencing ◽  
Molecular Mechanisms ◽  
Reductase Activity ◽  
The United States ◽  
Microbial Pathogens ◽  
Content Type ◽  
Time To Death ◽  
Expression Studies ◽  
Iron Reductase

ABSTRACTPassage in mice of opportunistic pathogens such asCryptococcus neoformansis known to increase virulence, but little is known about the molecular mechanisms involved in virulence adaptation. Serial mouse passage of nine environmental strains of serotype AC. neoformansidentified two highly adapted virulent strains that showed a 4-fold reduction in time to death after four passages. Transcriptome sequencing expression studies demonstrated increased expression of aFRE3-encoded iron reductase in the two strains but not in a control strain that did not demonstrate increased virulence during mouse passage.FRE3was shown to express an iron reductase activity and to play a role in iron-dependent growth ofC. neoformans. Overexpression ofFRE3in the two original environmental strains increased growth in the macrophage cell line J774.16 and increased virulence. These data demonstrate a role forFRE3in the virulence ofC. neoformansand demonstrate how the increased expression of such a “virulence acquisition gene” during the environment-to-mammal transition, can optimize the virulence of environmental strains in mammalian hosts.IMPORTANCECryptococcus neoformansis a significant global fungal pathogen that also resides in the environment. Recent studies have suggested that the organism may undergo microevolution in the host. However, little is known about the permitted genetic changes facilitating the adaptation of environmental strains to mammalian hosts. The present studies subjected environmental strains isolated from several metropolitan areas of the United States to serial passages in mice. Transcriptome sequencing expression studies identified the increased expression of an iron reductase gene,FRE3, in two strains that adapted in mice to become highly virulent, and overexpression ofFRE3recapitulated the increased virulence after mouse passage. Iron reductase in yeast is important to iron uptake in a large number of microbial pathogens. These studies demonstrate the capacity ofC. neoformansto show reproducible changes in the expression levels of small numbers of genes termed “virulence adaptation genes” to effectively increase pathogenicity during the environment-to-mammal transition.

scholarly journals Ferric iron reductase activity of LuxG from Photobacterium leiognathi

2016 ◽  
Vol 52 (4) ◽  
pp. 495-499 ◽  
Author(s):  
Eui Ho Lee ◽  
Ki Seok Nam ◽  
Seon Kwang Lee ◽  
Eugeney Oh ◽  
Chan Yong Lee
Keyword(s):  
Ferric Iron ◽  
Reductase Activity ◽  
Photobacterium Leiognathi ◽  
Iron Reductase

scholarly journals Iron Deficiency Induced Changes in Iron Reductase Activity in Papaya Roots

2002 ◽  
Vol 127 (2) ◽  
pp. 184-187 ◽  
Author(s):  
Thomas E. Marler ◽  
Ruben dela Cruz ◽  
Andrea L. Blas
Keyword(s):  
Glycine Max ◽  
Iron Deficiency ◽  
Carica Papaya ◽  
Reductase Activity ◽  
Fe Deficiency ◽  
Root Tip ◽  
Root Tips ◽  
Soybean Line ◽  
Induced Changes ◽  
Iron Reductase

Four papaya (Carica papaya L.) cultivars were cultured aeroponically or in perlite to determine the magnitude, timing, and root locality of Fe reductase induced by Fe deficiency. Five soybean [Glycine max (L.) Merrill] lines with a known range of Fe-deficiency chlorosis scores were cultured in perlite for comparison. Speed of inducement of Fe reductase activity was determined in plants cultured without Fe for 0 to 17 days. Location of Fe reductase activity was determined by sectioning roots from the tip to 60 to 70 mm proximal to the root tip from plants cultured without Fe for 16 to 19 days. The Fe reductase system was induced in all papaya cultivars after 7 to 11 days without Fe, and activity increased through 17 days. Iron reductase activity in all papaya cultivars was comparable to the most tolerant soybean line. The zone of highest activity was the apical 10 mm of roots. These results indicate that papaya roots are highly efficient in induced Fe reductase activity. The highest activity in root tips underscores the importance of maintaining a healthy, continually growing root system with numerous growing points when culturing papaya in alkaline substrates.

scholarly journals Iron Reductase for Magnetite Synthesis in the Magnetotactic Bacterium Magnetospirillum magnetotacticum

1999 ◽  
Vol 181 (7) ◽  
pp. 2142-2147 ◽  
Author(s):  
Yasushi Noguchi ◽  
Taketomo Fujiwara ◽  
Katsuhiko Yoshimatsu ◽  
Yoshihiro Fukumori
Keyword(s):  
Ferric Iron ◽  
Reductase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Flavin Mononucleotide ◽  
Homogeneous State ◽  
Magnetotactic Bacterium ◽  
Magnetospirillum Magnetotacticum ◽  
Iron Reductase

ABSTRACT Ferric iron reductase was purified from magnetotactic bacteriumMagnetospirillum (formerly Aquaspirillum)magnetotacticum (ATCC 31632) to an electrophoretically homogeneous state. The enzyme was loosely bound on the cytoplasmic face of the cytoplasmic membrane and was found more frequently in magnetic cells than in nonmagnetic cells. The molecular mass of the purified enzyme was calculated upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be about 36 kDa, almost the same as that calibrated by gel filtration analysis. The enzyme required NADH and flavin mononucleotide (FMN) as optimal electron donor and cofactor, respectively, and the activity was strongly inhibited by Zn2+ acting as a partial mixed-type inhibitor. TheKm values for NADH and FMN were 4.3 and 0.035 μM, respectively, and the Ki values for Zn2+ were 19.2 and 23.9 μM for NADH and FMN, respectively. When the bacterium was grown in the presence of ZnSO4, the magnetosome number in the cells and the ferric iron reductase activity declined in parallel with an increase in the ZnSO4 concentration of the medium, suggesting that the ferric iron reductase purified in the present study may participate in magnetite synthesis.

scholarly journals Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L.) and association with seed iron accumulation QTL

2010 ◽  
Vol 10 (1) ◽  
pp. 215 ◽  
Author(s):  
Matthew W Blair ◽  
Sharon JB Knewtson ◽  
Carolina Astudillo ◽  
Chee-Ming Li ◽  
Andrea C Fernandez ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Reductase Activity ◽  
Iron Accumulation ◽  
Phaseolus Vulgaris L ◽  
Iron Reductase

scholarly journals Multiple mechanisms for the regulation of haem synthesis during erythroid cell differentiation. Possible role for coproporphyrinogen oxidase

1991 ◽  
Vol 275 (2) ◽  
pp. 321-326 ◽  
Author(s):  
L H Conder ◽  
S I Woodard ◽  
H A Dailey
Keyword(s):  
De Novo ◽  
Culture Media ◽  
Reductase Activity ◽  
Erythroid Cell ◽  
Erythroid Precursor ◽  
Protoporphyrinogen Oxidase ◽  
Coproporphyrinogen Oxidase ◽  
Haem Biosynthesis ◽  
Erythroid Cell Differentiation ◽  
Iron Reductase

Murine erythroleukaemia (MEL) cells are virus-transformed erythroid precursor cells that, when induced to differentiate by dimethyl sulphoxide (DMSO), will initiate haem biosynthesis by the induction and synthesis de novo of all of the enzymes of the haem-biosynthetic pathway. The activities of porphobilinogen (PBG) deaminase (EC 4.3.1.8), coproporphyrinogen oxidase (EC 1.3.3.3), protoporphyrinogen oxidase (EC 1.3.3.4), ferrochelatase (EC 4.99.1.1) and NADH:ferric iron reductase, as well as the synthesis of the enzyme ferrochelatase and the levels of excreted porphyrins, were monitored during DMSO-induced differentiation of MEL cells in culture. The data demonstrate that PBG deaminase and protoporphyrinogen oxidase activities rise rapidly and early, in comparison with ferrochelatase activity, which rises more slowly, and coproporphyrinogen oxidase activity, which decreases by 60% within 24 h of induction before returning to initial levels by 72 h. NADH:ferric iron reductase activity increases slightly, but is always present at levels higher than needed for haem synthesis. Total immunoprecipitable ferrochelatase also rises slowly and parallels the increase in its activity, suggesting that it is not synthesized early in a slowly processed precursor form. Examination of culture media demonstrated that, whereas excretion of protoporphyrin and coproporphyrin occurs within 24 h of induction, coproporphyrin is excreted in amounts 4-15 times greater than protoporphyrin.

scholarly journals Utilization of iron-catecholamine complexes involving ferric reductase activity in Listeria monocytogenes.

1997 ◽  
Vol 65 (7) ◽  
pp. 2778-2785 ◽  
Author(s):  
V Coulanges ◽  
P Andre ◽  
O Ziegler ◽  
L Buchheit ◽  
D J Vidon
Keyword(s):  
Listeria Monocytogenes ◽  
Reductase Activity ◽  
Ferric Reductase

Iron acquisition by oral hemolytic spirochetes: isolation of a hemin-binding protein and identification of iron reductase activity

1996 ◽  
Vol 42 (10) ◽  
pp. 1072-1079 ◽  
Author(s):  
D. Scott ◽  
R. Siboo ◽  
E. C. S. Chan
Keyword(s):  
Binding Protein ◽  
Reductase Activity ◽  
Iron Acquisition ◽  
Ammonium Citrate ◽  
Ferric Ammonium Citrate ◽  
Affinity Column ◽  
Treponema Denticola ◽  
Apparent Homogeneity ◽  
Iron Reductase

Oral anaerobic spirochetes (OAS) have been implicated in the etiology of periodontal disease. To adapt to the environment of the subgingiva, OAS must be able to acquire iron from limited sources. OAS have previously been shown not to produce siderophores but are β-hemolytic and can bind hemin via a proteinaceous 47-kDa outer membrane sheath (OMS) receptor. Present studies show that [3H]hemin is not transported into the cytoplasm, that hemin and ferric ammonium citrate, as the sole iron sources, can support the growth of OAS and that protoporphyrin IX and Congo red are inhibitory, thereby implying an important in vivo role for hemin as an iron source. Treponema denticola ATCC 35405 produces an iron reductase. The iron reductase can reduce the central ferric iron moiety of hemin. The 47-kDa OMS hemin-binding protein has been purified to apparent homogeneity by methanol–chloroform extraction of cellular lipoproteins and the use of a hemin–agarose bead affinity column. A model of iron acquisition by OAS is presented.Key words: Treponema denticola, hemin-binding protein, iron limitation, iron reductase.

scholarly journals A thioredoxin reductase-like protein from the thermophile, Thermus scotoductus SA-01, displaying iron reductase activity

2010 ◽  
Vol 302 (2) ◽  
pp. 182-188 ◽  
Author(s):  
Phillip Armand Bester ◽  
Derek Litthauer ◽  
Lizelle A. Piater ◽  
Esta Van Heerden
Keyword(s):  
Reductase Activity ◽  
Thioredoxin Reductase ◽  
Iron Reductase

scholarly journals Functional Assembly of Caenorhabditis elegans Cytochrome b-2 (Cecytb-2) into Phospholipid Bilayer Nanodisc with Enhanced Iron Reductase Activity

Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 96
Author(s):  
Hamed A. Abosharaf ◽  
Yuki Sakamoto ◽  
Aliaa M. Radwan ◽  
Keisuke Yuzu ◽  
Mika Fujimura ◽  
...  
Keyword(s):  
Reductase Activity ◽  
Model Organism ◽  
Phospholipid Bilayer ◽  
Ferric Reductase ◽  
Anaerobic Conditions ◽  
C Elegans ◽  
Cytochrome B561 ◽  
Ferrous Heme ◽  
Substrate Concentrations ◽  
Iron Reductase

Among seven homologs of cytochrome b561 in a model organism C. elegans, Cecytb-2 was confirmed to be expressed in digestive organs and was considered as a homolog of human Dcytb functioning as a ferric reductase. Cecytb-2 protein was expressed in Pichia pastoris cells, purified, and reconstituted into a phospholipid bilayer nanodisc. The reconstituted Cecytb-2 in nanodisc environments was extremely stable and more reducible with ascorbate than in a detergent-micelle state. We confirmed the ferric reductase activity of Cecytb-2 by analyzing the oxidation of ferrous heme upon addition of ferric substrate under anaerobic conditions, where clear and saturable dependencies on the substrate concentrations following the Michaelis–Menten equation were observed. Further, we confirmed that the ferric substrate was converted to a ferrous state by using a nitroso-PSAP assay. Importantly, we observed that the ferric reductase activity of Cecytb-2 became enhanced in the phospholipid bilayer nanodisc.

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