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Hemoprotein reductant

Nino A Espinas, Koichi Kobayashi, Yasushi Sato, Nobuyoshi Mochizuki, Kaori Takahashi, Ryouichi Tanaka, Tatsuru Masuda
Heme is involved in various biological processes as a cofactor of hemoproteins located in various organelles. In plant cells, heme is synthesized by two isoforms of plastid-localized ferrochelatase, FC1 and FC2. In this study, by characterizing Arabidopsis T-DNA insertional mutants, we showed that the allocation of heme is differentially regulated by ferrochelatase isoforms in plant cells. Analyses of weak (fc1-1) and null (fc1-2) mutants suggest that FC1-producing heme is required for initial growth of seedling development...
2016: Frontiers in Plant Science
Chihiro Kitatsuji, Kozue Izumi, Shusuke Nambu, Masaki Kurogochi, Takeshi Uchida, Shin-ichiro Nishimura, Kazuhiro Iwai, Mark R O'Brian, Masao Ikeda-Saito, Koichiro Ishimori
The Bradyrhizobium japonicum transcriptional regulator Irr (iron response regulator) is a key regulator of the iron homeostasis, which is degraded in response to heme binding via a mechanism that involves oxidative modification of the protein. Here, we show that heme-bound Irr activates O2 to form highly reactive oxygen species (ROS) with the "active site conversion" from heme iron to non-heme iron to degrade itself. In the presence of heme and reductant, the ROS scavenging experiments show that Irr generates H2O2 from O2 as found for other hemoproteins, but H2O2 is less effective in oxidizing the peptide, and further activation of H2O2 is suggested...
January 5, 2016: Scientific Reports
O V Gnedenko, A S Ivanov, E O Yablokov, S A Usanov, D V Mukha, G V Sergeev, A V Kuzikov, T V Bulko, N E Moskaleva, V V Shumyantseva, A I Archakov
Molecular interactions between proteins redox partners (cytochromes Р450 3А4, 3А5 and cytochrome b5) within the monooxygenase system, which is known to be involved in drug biotransformation, were investigated. Human cytochromes Р450 3А4 and 3А5 (CYP3A4 and CYP3A5) form complexes with various cytochromes b5: the microsomal (b5mc) and mitochondrial (b5om) forms of this protein, as well as with 2 "chimeric" proteins, b5(om-mc), b5(mc-om). Kinetic constants and equilibrium dissociation constants were determined by the SPR biosensor...
July 2015: Biomedit︠s︡inskai︠a︡ Khimii︠a︡
Isabel Askenasy, Joseph M Pennington, Yeqing Tao, Alan G Marshall, Nicolas L Young, Weifeng Shang, M Elizabeth Stroupe
Assimilatory NADPH-sulfite reductase (SiR) from Escherichia coli is a structurally complex oxidoreductase that catalyzes the six-electron reduction of sulfite to sulfide. Two subunits, one a flavin-binding flavoprotein (SiRFP, the α subunit) and the other an iron-containing hemoprotein (SiRHP, the β subunit), assemble to make a holoenzyme of about 800 kDa. How the two subunits assemble is not known. The iron-rich cofactors in SiRHP are unique because they are a covalent arrangement of a Fe4S4 cluster attached through a cysteine ligand to an iron-containing porphyrinoid called siroheme...
July 31, 2015: Journal of Biological Chemistry
Naihao Lu, Jiayu Li, Xiaoming Ren, Rong Tian, Yi-Yuan Peng
Hypochlorous acid (HOCl) is elevated in many inflammatory diseases and causes the accumulation of free iron. Through the Fenton reaction, free iron has the ability to generate free radicals and subsequently is toxic. Recent studies have demonstrated that HOCl participates in heme destruction of hemoglobin (Hb) and free iron release. In this study, it was showed that nitrite (NO2(-)) could prevent HOCl-mediated Hb heme destruction and free iron release. Also, NO2(-) prevented HOCl-mediated loss of Hb peroxidase activity...
August 5, 2015: Chemico-biological Interactions
Darius J R Lane, Dong-Hun Bae, Angelica M Merlot, Sumit Sahni, Des R Richardson
Iron and ascorbate are vital cellular constituents in mammalian systems. The bulk-requirement for iron is during erythropoiesis leading to the generation of hemoglobin-containing erythrocytes. Additionally; both iron and ascorbate are required as co-factors in numerous metabolic reactions. Iron homeostasis is controlled at the level of uptake; rather than excretion. Accumulating evidence strongly suggests that in addition to the known ability of dietary ascorbate to enhance non-heme iron absorption in the gut; ascorbate regulates iron homeostasis...
April 2015: Nutrients
V V Shumyantseva, A A Makhova, T V Bulko, R Bernhardt, A V Kuzikov, E V Shich, V G Kukes, A I Archakov
The influence of the biologically active compound taurine on the stability and catalytic properties of the hemoprotein cytochrome P450 3A4 has been investigated. The catalytic properties were analyzed by electrochemical methods (cyclic and square-wave voltammetry) using cytochrome P450 3A4 immobilized on the electrode. Taurine at concentrations in the range 10-70 µM stimulated the electrochemical reduction of cytochrome P450 3A4, and the reduction was the highest (115 ± 3%) in the presence of 50 µM taurine...
March 2015: Biochemistry. Biokhimii︠a︡
J-P Mahy, J-D Maréchal, R Ricoux
The design of artificial hemoproteins that could catalyze selective oxidations using clean oxidants such as O2 or H2O2 under ecocompatible conditions constitutes a real challenge for a wide range of industrial applications. In vivo, such reactions are performed by heme-thiolate proteins, cytochromes P450, which catalyze the oxidation of substrates by dioxygen in the presence of electrons delivered from NADPH by cytochrome P450 reductase. Several strategies were used to design new artificial hemoproteins that mimic these enzymes...
February 14, 2015: Chemical Communications: Chem Comm
Hangjun Ke, Paul A Sigala, Kazutoyo Miura, Joanne M Morrisey, Michael W Mather, Jan R Crowley, Jeffrey P Henderson, Daniel E Goldberg, Carole A Long, Akhil B Vaidya
Heme is an essential cofactor for aerobic organisms. Its redox chemistry is central to a variety of biological functions mediated by hemoproteins. In blood stages, malaria parasites consume most of the hemoglobin inside the infected erythrocytes, forming nontoxic hemozoin crystals from large quantities of heme released during digestion. At the same time, the parasites possess a heme de novo biosynthetic pathway. This pathway in the human malaria parasite Plasmodium falciparum has been considered essential and is proposed as a potential drug target...
December 12, 2014: Journal of Biological Chemistry
Roman Davydov, Mikhail Laryukhin, Amy Ledbetter-Rogers, Masanori Sono, John H Dawson, Brian M Hoffman
The fleeting ferric peroxo and hydroperoxo intermediates of dioxygen activation by hemoproteins can be readily trapped and characterized during cryoradiolytic reduction of ferrous hemoprotein-O2 complexes at 77 K. Previous cryoannealing studies suggested that the relaxation of cryogenerated hydroperoxoferric intermediates of myoglobin (Mb), hemoglobin, and horseradish peroxidase (HRP), either trapped directly at 77 K or generated by cryoannealing of a trapped peroxo-ferric state, proceeds through dissociation of bound H2O2 and formation of the ferric heme without formation of the ferryl porphyrin π-cation radical intermediate, compound I (Cpd I)...
August 5, 2014: Biochemistry
O V Gnedenko, A S Ivanov, E O Iablokov, S A Usanov, D V Mukha, G V Sergeev, A V Kuzikov, N E Moskaleva, T V Bulko, V V Shumiantseva, A I Archakov
Molecular interactions between proteins redox partners (cytochromes P450 3A4, 3A5 and cytochrome b5) within the monooxygenase system, which is known to be involved in drug biotransformation, were investigated. Human cytochromes P450 3A4 and 3A5 (CYP3A4 and CYP3A5) form complexes with various cytochromes b5: the microsomal (b5mc) and mitochondrial (b5om) forms of this protein, as well as with 2 "chimeric" proteins, b5(om-mc), b5(mc-om). Kinetic constants and equilibrium dissociation constants were determined by the SPR biosensor...
January 2014: Biomedit︠s︡inskai︠a︡ Khimii︠a︡
Alan R Brash, Narayan P Niraula, William E Boeglin, Zahra Mashhadi
In the course of exploring the scope of catalase-related hemoprotein reactivity toward fatty acid hydroperoxides, we detected a novel candidate in the cyanobacterium Nostoc punctiforme PCC 73102. The immediate neighboring upstream gene, annotated as "cyclooxygenase-2," appeared to be a potential fatty acid heme dioxygenase. We cloned both genes and expressed the cDNAs in Escherichia coli, confirming their hemoprotein character. Oxygen electrode recordings demonstrated a rapid (>100 turnovers/s) reaction of the heme dioxygenase with oleic and linoleic acids...
May 9, 2014: Journal of Biological Chemistry
Loic Stefan, Thomas Lavergne, Nicolas Spinelli, Eric Defrancq, David Monchaud
The structure of the double helix of deoxyribonucleic acid (DNA, also called duplex-DNA) was elucidated sixty years ago by Watson, Crick, Wilkins and Franklin. Since then, DNA has continued to hold a fascination for researchers in diverse fields including medicine and nanobiotechnology. Nature has indeed excelled in diversifying the use of DNA: beyond its canonical role of repository of genetic information, DNA could also act as a nanofactory able to perform some complex catalytic tasks in an enzyme-mimicking manner...
March 7, 2014: Nanoscale
Guillaume Suárez, Christian Santschi, Vera I Slaveykova, Olivier J F Martin
Reactive oxygen species play a key role in cell signalling and oxidative stress mechanisms, therefore, sensing their production by living organisms is of fundamental interest. Here we describe a novel biosensing method for extracellular detection of endogenous hydrogen peroxide (H2O2). The method is based on the enhancement of the optical absorption spectrum of the hemoprotein cytochrome c when loaded into a highly scattering random medium. Such a configuration enables, in contrast to existing techniques, non-invasive and dynamic detection of the oxidation of cyt c in the presence of H2O2 with unprecedented sensitivity...
2013: Scientific Reports
C Ip
The present study was designed to examine the effect of selenium deficiency on the activities of heme hydroperoxidase and glutathione peroxidases in the liver of male rats maintained on either a 5% or a 25% corn oil diet and treated with phenobarbital. Our results showed that although the basal levels of cytochrome P-450 and heme hydroperoxidase were unaffected by selenium deficiency, the magnitude of phenobarbital induction was impaired because of the depletion of this trace element. This effect was accentuated especially in rats with a high-fat intake...
April 1983: Biological Trace Element Research
Mariano Venanzi, Sabrina Cianfanelli, Antonio Palleschi
A new metalloenzyme formed by a Fe(III)-mesoporphyrin IX functionalized by two helical decapeptides was synthesized to mimic function and structural features of a hemoprotein active site. Each decapeptide comprises six 2-aminoisobutyric acid residues, which constrain the peptide to attain a helical conformation, and three glutamic residues for improving the solubility of the catalyst in aqueous solutions. The new compound shows a marked amphiphilic character, featuring a polar outer surface and a hydrophobic inner cavity that hosts the reactants in a restrained environment where catalysis may occur...
January 2014: Journal of Peptide Science: An Official Publication of the European Peptide Society
Mizanur M Rahaman, Adam C Straub
The vertebrate globins are a group of hemoproteins with the intrinsic capacity to regulate gaseous ligands and redox signaling required for cardiovascular biology. This graphical review will provide a comprehensive synopsis of somatic cardiovascular globins focusing on expression, function and redox signaling - an emerging area in both physiology and disease.
2013: Redox Biology
Barbara Wegiel, Zsuzsanna Nemeth, Matheus Correa-Costa, Andrew C Bulmer, Leo E Otterbein
SIGNIFICANCE: Heme degradation, which was described more than 30 years ago, is still very actively explored with many novel discoveries on its role in various disease models every year. RECENT ADVANCES: The heme oxygenases (HO) are metabolic enzymes that utilize NADPH and oxygen to break apart the heme moiety liberating biliverdin (BV), carbon monoxide (CO), and iron. Heme that is derived from hemoproteins can be toxic to the cells and if not removed immediately, it causes cell apoptosis and local inflammation...
April 10, 2014: Antioxidants & Redox Signaling
Kei Takahashi, Yuki Oda, Yasuyuki Toyoda, Tatsuki Fukami, Tsuyoshi Yokoi, Miki Nakajima
PURPOSE: Cytochrome b5 (b5) is a hemoprotein that transfers electrons to several enzymes to fulfill functions in fatty acid desaturation, methemoglobin reduction, steroidogenesis, and drug metabolism. Despite the importance of b5, the regulation of b5 expression in human liver remains largely unknown. We investigated whether microRNA (miRNA) might be involved in the regulation of human b5. METHODS: Twenty-four human liver specimens were used for correlation analysis...
March 2014: Pharmaceutical Research
Jie Pan, Qiming Xu, Ying-Wu Lin, Fangfang Zhong, Xiangshi Tan
Human soluble guanylate cyclase (hsGC), a NO sensor/NO receptor of a heterodimeric hemoprotein, plays a critical role in the NO-sGC-cGMP signaling pathway, and also reveals a novel nitrite reductase activity. This indicates that hsGC could activate itself by catalytic reduction of nitrite to NO instead of receiving NO from nitric oxide synthase (NOS), which provides valuable insight into the physiological function of the homodimeric hsGC.
August 28, 2013: Chemical Communications: Chem Comm
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