Redesigning the Blue Copper Azurin into a Redox-Active Mononuclear Nonheme Iron Protein: Preparation and Study of Fe(II)-M121E Azurin

2014 ◽  
Vol 136 (35) ◽  
pp. 12337-12344 ◽  
Author(s):  
Jing Liu ◽  
Katlyn K. Meier ◽  
Shiliang Tian ◽  
Jun-long Zhang ◽  
Hongchao Guo ◽  
...  
Keyword(s):  
Nonheme Iron ◽  
Protein Preparation ◽  
Blue Copper ◽  
Iron Protein ◽  
Redox Active

Site of action of nonheme iron in the malate (flavine adenine dinucleotide) pathway of Mycobacterium phlei

1976 ◽  
Vol 22 (7) ◽  
pp. 1054-1057 ◽  
Author(s):  
A. K. Tyagi ◽  
T. L. Prasada Reddy ◽  
T. A. Venkitasubramanian
Keyword(s):  
Electron Transport ◽  
Ultraviolet Light ◽  
Nonheme Iron ◽  
Paramagnetic Resonance ◽  
Iron Protein ◽  
Mycobacterium Phlei ◽  
Diphenyl Tetrazolium Bromide ◽  
Electron Paramagnetic ◽  
Soluble Components ◽  
Malate Oxidation

Irradiation with ultraviolet light (360 nm) of cell-free extracts, electron-transport particles, and soluble components from Mycobacterium phlei resulted in the loss of malate oxidation by the flavine adenine dinucleotide pathway both in cell-free extracts and reconstituted systems. Addition of vitamin K1 restored the loss to the extent of 14% and 11% in cell-free extracts and reconstituted systems respectively. Electron-transport particles from M. phlei upon reduction with malate exhibited electron-paramagnetic resonance signals at g = 2.002 and 1.94, characteristic of napthosemiquinone and nonheme iron protein, respectively. Upon irradiating the particles with ultraviolet light (360 nm) these signals were not observed. Particulate flavine-adenine-dinucleotide-dependent malate dehydrogenase (EC 1.1.1.37) of M. phlei assayed by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide and phenazine methosulfate–2,6-dichlorophenolindophenol systems, which trap electrons at cytochrome c and at the flavine level respectively, was inhibited by o-phenanthroline. These observations suggest that nonheme iron protein is sensitive to ultraviolet light (360 nm) and participates before or in combination with flavine in the malate (flavine adenine dinucleotide) pathway of M. phlei.

[65] Isolation of adrenal cortex nonheme iron protein

1967 ◽  
pp. 362-367 ◽  
Author(s):  
T. Omura ◽  
E. Sanders ◽  
D.Y. Cooper ◽  
R.W. Estabrook
Keyword(s):  
Adrenal Cortex ◽  
Nonheme Iron ◽  
Iron Protein

Characterization of the ω-hydroxylase of Pseudomonas oleovorans as a nonheme iron protein

1977 ◽  
Vol 183 (2) ◽  
pp. 528-537 ◽  
Author(s):  
Richard T. Ruettinger ◽  
Gary R. Griffith ◽  
Minor J. Coon
Keyword(s):  
Nonheme Iron ◽  
Pseudomonas Oleovorans ◽  
Iron Protein

Vascular release of nonheme iron in perfused rabbit lungs

2001 ◽  
Vol 280 (3) ◽  
pp. L474-L481 ◽  
Author(s):  
Yuh-Chin T. Huang ◽  
Andrew J. Ghio ◽  
Eva Nozik-Grayck ◽  
Claude A. Piantadosi
Keyword(s):  
Iron Homeostasis ◽  
Ischemia Reperfusion ◽  
Nonheme Iron ◽  
Similar Amount ◽  
Excess Iron ◽  
Exchange Inhibitor ◽  
Active Iron ◽  
Vascular Space ◽  
Redox Active ◽  
Vascular Compartment

In this study, we hypothesized that the lung actively releases excess iron into the circulation to regulate iron homeostasis. We measured nonheme iron (NHFe) in the perfusate of control isolated perfused rabbit lungs and lungs with ischemia-reperfusion (I/R) ventilated with normoxic (21% O2) or hypoxic (95% N2) gas mixtures. Some were perfused with bicarbonate-free (HEPES) buffer or treated with the anion exchange inhibitor DIDS. The control lungs released ∼0.25 μg/ml of NHFe or 20% of the total lung NHFe into the vascular space that was not complexed with ferritin, transferrin, or lactoferrin or bleomycin reactive. The I/R lungs released a similar amount of NHFe during ischemia and some bleomycin-detectable iron during reperfusion. NHFe release was attenuated by ∼50% in both control and ischemic lungs by hypoxia and by >90% in control lungs and ∼60% in ischemic lungs by DIDS and HEPES. Reperfusion injury was not affected by DIDS or HEPES but was attenuated by hypoxia. These results indicate that biologically nonreactive nonheme iron is released rapidly by the lung into the vascular space via mechanisms that are linked to bicarbonate exchange. During prolonged ischemia, redox-active iron is also released into the vascular compartment by other mechanisms and may contribute to lung injury.

scholarly journals The number of iron atoms in the paramagnetic center (G =1.94) of reduced putidaredoxin, a nonheme iron protein.

1968 ◽  
Vol 59 (3) ◽  
pp. 959-965 ◽  
Author(s):  
J. C. Tsibris ◽  
R. L. Tsai ◽  
I. C. Gunsalus ◽  
W. H. Orme-Johnson ◽  
R. E. Hansen ◽  
...  
Keyword(s):  
Paramagnetic Center ◽  
Nonheme Iron ◽  
Iron Protein

Properties of the particulate enzyme F420-reducing hydrogenase isolated from Methanospirillum hungatei

1987 ◽  
Vol 33 (10) ◽  
pp. 896-904 ◽  
Author(s):  
G. Dennis Sprott ◽  
Kathleen M. Shaw ◽  
Terry J. Beveridge
Keyword(s):  
Gel Filtration ◽  
Methanobacterium Thermoautotrophicum ◽  
Methanosarcina Barkeri ◽  
Nonheme Iron ◽  
Anaerobic Conditions ◽  
Hydrophobic Properties ◽  
Iron Protein ◽  
Methanospirillum Hungatei ◽  
Cytoplasmic Membranes ◽  
Spectrum Characteristic

F420-reducing hydrogenase was isolated from spheroplast lysates of Methanospirillum hungatei by sedimentation, followed by sucrose gradient centrifugations and gel filtration. These procedures resulted in a preparation free of methyl reductase and cytoplasmic membranes. The hydrogenase was a brown protein with an absorption spectrum characteristic for a nonheme iron protein. In electron micrographs it was a coin-shaped, multisubunit protein complex of 15.9 nm diameter with a central depression on one surface. On phenyl Sepharose chromatography the hydrogenase exhibited hydrophobic properties. The holoenzyme was about 720 kilodaltons (kDa), composed of 50.7 and 30.7 kDa subunits in a ratio of 1:3. Each enzyme particle contained 6 or 7 Ni2+ atoms. H2-dependent reduction of F420 activity was readily, but transiently, reactivated by anaerobic conditions following exposure of the enzyme to air. Mg2+ or Ca2+ were stimulatory, but added FAD was not required. Antibody raised against the purified hydrogenase of strain GP1 gave a negative reaction with extracts of nine other methanogens and a reaction of identity with strain JF1 and Methanosarcina barkeri MS. Direct comparisons with the hyrogenase from Methanobacterium thermoautotrophicum ΔH revealed striking differences in subunit composition and in the acidity of the holoenzyme.

scholarly journals Isolation and Role of Nonheme Iron Protein in Clostridium botulinum1

1968 ◽  
Vol 16 (2) ◽  
pp. 207-211
Author(s):  
John K. Dyer ◽  
A. W. Anderson
Keyword(s):  
Nonheme Iron ◽  
Iron Protein
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