Spectroscopic Measurement of a Long-Predicted Active Site pKin Iron-Superoxide Dismutase fromEscherichia coli†

Biochemistry ◽  
1997 ◽  
Vol 36 (16) ◽  
pp. 4916-4924 ◽  
Author(s):  
David L. Sorkin ◽  
Anne-Frances Miller
Keyword(s):  
Superoxide Dismutase ◽  
Active Site ◽  
Spectroscopic Measurement ◽  
Iron Superoxide Dismutase ◽  
Fromescherichia Coli

scholarly journals pH-dependent inhibition by azide and fluoride of the iron superoxide dismutase from Propionibacterium shermanii

1998 ◽  
Vol 331 (2) ◽  
pp. 403-407 ◽  
Author(s):  
Beate MEIER ◽  
Christoph SCHERK ◽  
Marius SCHMIDT ◽  
Fritz PARAK
Keyword(s):  
Superoxide Dismutase ◽  
Active Site ◽  
Low Ph ◽  
Superoxide Dismutases ◽  
Iron Superoxide Dismutase ◽  
Propionibacterium Shermanii ◽  
Hydroxyl Anion ◽  
Dependent Inhibition ◽  
Ph Dependent ◽  
A Minor

The iron-containing superoxide dismutase from Propionibacterium shermanii shows, in contrast with other iron superoxide dismutases, only a minor inhibition by azide or fluoride (10–100 mM) of up to 23% at pH 7.8. The activity of the protein with Mn bound to the active site was not diminished under the same conditions. The binding constant between azide and the Fe3+ ion was determined as approx. 2 mM and for fluoride approx. 2.3 mM; they are so far comparable to those known for other iron superoxide dismutases. This seems to be a discrepancy because all other iron superoxide dismutases so far known are described as being inhibited by 50–70% by 10 mM azide. However, towards lower pH there was a drastically increased inhibition by both anions. At pH 6.8 about 80% inhibition was exhibited by azide or fluoride at a concentration of 10 mM or higher. In contrast, on increasing the pH, azide or fluoride still bound to the Fe3+ at the active site but their inhibition capacity decreased. This observation implies that both anions bind to the metal at a position that is empty at low pH, whereas at higher pH water or a negatively charged hydroxyl anion is bound. It is likely that the superoxide anion binds to the same position and has to replace the sixth ligand, leading to a diminished catalytic activity of the superoxide dismutase owing to steric and/or electrostatic inhibition of the ligand.

Catalytic role of iron-superoxide dismutase in hydrogen abstraction by super oxide radical anion from ascorbic acid

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86650-86662 ◽  
Author(s):  
Manish K. Tiwari ◽  
Phool C. Mishra
Keyword(s):  
Ascorbic Acid ◽  
Superoxide Dismutase ◽  
Active Site ◽  
Radical Anion ◽  
Superoxide Radical ◽  
Hydrogen Abstraction ◽  
Iron Superoxide Dismutase ◽  
Superoxide Radical Anion ◽  
Catalytic Role

The catalytic role of iron-superoxide dismutase (Fe-SOD) in the working of ascorbic acid (AA) as a superoxide radical anion scavenger has been studied by employing a model developed recently for the active site of the enzyme.

The Conserved Residue Tyrosine 34 Is Essential for Maximal Activity of Iron−Superoxide Dismutase fromEscherichia coli†

Biochemistry ◽  
1997 ◽  
Vol 36 (16) ◽  
pp. 4925-4933 ◽  
Author(s):  
Therese Hunter ◽  
Kazunori Ikebukuro ◽  
William H. Bannister ◽  
Joe V. Bannister ◽  
Gary J. Hunter
Keyword(s):  
Superoxide Dismutase ◽  
Maximal Activity ◽  
Iron Superoxide Dismutase ◽  
Fromescherichia Coli ◽  
Conserved Residue

scholarly journals The primary structure of iron superoxide dismutase fromEscherichia coli

FEBS Letters ◽  
1987 ◽  
Vol 221 (1) ◽  
pp. 87-90 ◽  
Author(s):  
M.Eugenia Schininà ◽  
Letizia Maffey ◽  
Donatella Barra ◽  
Francesco Bossa ◽  
Krystyna Puget ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Primary Structure ◽  
Iron Superoxide Dismutase ◽  
Fromescherichia Coli

Effect of Hubs in Amino Acid Network on Iron Superoxide Dismutase Stability

2015 ◽  
Vol 10 (2) ◽  
pp. 232-239
Author(s):  
Yanrui Ding ◽  
Xueqin Wang ◽  
Zhaolin Mou
Keyword(s):  
Superoxide Dismutase ◽  
Amino Acid ◽  
Iron Superoxide Dismutase

The iron content of iron superoxide dismutase: determination by anomalous scattering

1983 ◽  
Vol 218 (1210) ◽  
pp. 119-126 ◽  
Keyword(s):  
Superoxide Dismutase ◽  
Iron Content ◽  
Three Dimensional ◽  
Anomalous Scattering ◽  
Total Iron Content ◽  
Iron Site ◽  
Iron Superoxide Dismutase ◽  
Density Map ◽  
The Difference ◽  
Electron Density Map

The number of iron atoms in the dimeric iron-containing superoxide dismutase from Pseudomonas ovalis and their atomic positions have been determined directly from anomalous scattering measurements on crystals of the native enzyme. To resolve the long-standing question of the total amount of iron per molecule for this class of dismutase, the occupancy of each site was refined against the measured Bijvoet differences. The enzyme is a symmetrical dimer with one iron site in each subunit. The iron position is 9 ņ from the intersubunit interface. The total iron content of the dimer is 1.2±0.2 moles per mole of protein. This is divided between the subunits in the ratio 0.65:0.55; the difference between them is probably not significant. Since each subunit contains, on average, slightly more than half an iron atom we conclude that the normal state of this enzyme is two iron atoms per dimer but that some of the metal is lost during purification of the protein. Although the crystals are obviously a mixture of holo- and apo-enzymes, the 2.9 Å electron density map is uniformly clean, even at the iron site. We conclude that the three-dimensional structures of the iron-bound enzyme and the apoenzyme are identical.

scholarly journals A tetrameric iron superoxide dismutase from the eucaryote Tetrahymena pyriformis.

1990 ◽  
Vol 265 (29) ◽  
pp. 17680-17687
Author(s):  
D Barra ◽  
M E Schininà ◽  
F Bossa ◽  
K Puget ◽  
P Durosay ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Tetrahymena Pyriformis ◽  
Iron Superoxide Dismutase

Iron-superoxide dismutase and monodehydroascorbate reductase transcripts accumulate in response to internode rubbing in tomato

2004 ◽  
Vol 327 (7) ◽  
pp. 679-686 ◽  
Author(s):  
Ichrak Ben Rejeb ◽  
Catherine Lenne ◽  
Nathalie Leblanc ◽  
Jean-Louis Julien ◽  
Saı̈da Ammar ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Monodehydroascorbate Reductase ◽  
Iron Superoxide Dismutase
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