Hydroxylamine-induced oxidation of ferrous nitrobindins

Hemoglobin and myoglobin are generally taken as molecular models of all-α-helical heme-proteins. On the other hand, nitrophorins and nitrobindins (Nb), which are arranged in 8 and 10 β-strands, respectively, represent the molecular models of all-β-barrel heme-proteins. Here, kinetics of the hydroxyl...

Full description

Saved in:
Bibliographic Details
Published in:Journal of biological inorganic chemistry 2022-08, Vol.27 (4-5), p.443-453
Main Authors: De Simone, Giovanna, Tundo, Grazia R., Coletta, Andrea, Coletta, Massimo, Ascenzi, Paolo
Format: Article
Language:English
Subjects:
Aging
Anaerobic conditions
Biochemistry
Biomedical and Life Sciences
Heme
Hemoglobin
Hydroxylamine
Inorganic chemistry
Iron
Life Sciences
Macular degeneration
Microbiology
Molecular modelling
Myoglobins
Original Paper
Oxidation
Proteins
Reactive nitrogen species
Stoichiometry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Hemoglobin and myoglobin are generally taken as molecular models of all-α-helical heme-proteins. On the other hand, nitrophorins and nitrobindins (Nb), which are arranged in 8 and 10 β-strands, respectively, represent the molecular models of all-β-barrel heme-proteins. Here, kinetics of the hydroxylamine- (HA-) mediated oxidation of ferrous Mycobacterium tuberculosis , Arabidopsis thaliana , and Homo sapiens nitrobindins ( Mt -Nb(II), At -Nb(II), and Hs -Nb(II), respectively), at pH 7.0 and 20.0 °C, are reported. Of note, HA displays antibacterial properties and is a good candidate for the treatment and/or prevention of reactive nitrogen species- (RNS-) linked aging-related pathologies, such as macular degeneration. Under anaerobic conditions, mixing the Mt -Nb(II), At -Nb(II), and Hs -Nb(II) solutions with the HA solutions brings about absorbance spectral changes reflecting the formation of the ferric derivative ( i.e. , Mt -Nb(III), At -Nb(III), and Hs -Nb(III), respectively). Values of the second order rate constant for the HA-mediated oxidation of Mt -Nb(II), At -Nb(II), and Hs -Nb(II) are 1.1 × 10 4  M −1  s −1 , 6.5 × 10 4  M −1  s −1 , and 2.2 × 10 4  M −1  s −1 , respectively. Moreover, the HA:Nb(II) stoichiometry is 1:2 as reported for ferrous deoxygenated and carbonylated all-α-helical heme-proteins. A comparative look of the HA reduction kinetics by several ferrous heme-proteins suggests that an important role might be played by residues (such as His or Tyr) in the proximity of the heme-Fe atom either coordinating it or not. In this respect, Nbs seem to exploit somewhat different structural aspects, indicating that redox mechanisms for the heme-Fe(II)-to-heme-Fe(III) conversion might differ between all-α-helical and all-β-barrel heme-proteins. Graphical abstract
ISSN:1432-1327
0949-8257
1432-1327
DOI:10.1007/s00775-022-01940-9