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Peroxiredoxin
Peroxiredoxins (Prxs, ; HGNC root symbol ''PRDX'') are a ubiquitous family of antioxidant enzymes that also control cytokine-induced peroxide levels and thereby mediate signal transduction in mammalian cells. The family members in humans are PRDX1, PRDX2, PRDX3, PRDX4, PRDX5, and PRDX6. The physiological importance of peroxiredoxins is indicated by their relative abundance (one of the most abundant proteins in erythrocytes after hemoglobin is peroxiredoxin 2). Their function is the reduction of peroxides, specifically hydrogen peroxide, alkyl hydroperoxides, and peroxynitrite. Classification Prxs were historically divided into three (mechanistic) classes: *Typical 2-Cys Prxs *Atypical 2-Cys Prxs and *1-Cys Prxs. The designation of "1-Cys" and "2-Cys" Prxs was introduced in 1994 as it was noticed that, among the 22 Prx sequences known at the time, only one Cys residue was absolutely conserved; this is the residue now recognized as the (required) peroxidatic cysteine, CP. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRDX5
Peroxiredoxin-5 (PRDX5), mitochondrial is a protein that in humans is encoded by the ''PRDX5'' gene, located on chromosome 11. This gene encodes a member of the six-member peroxiredoxin family of antioxidant enzymes. Like the other five members, PRDX5 is widely expressed in tissues but differs by its large subcellular distribution. In human cells, it has been shown that PRDX5 can be localized to mitochondria, peroxisomes, the cytosol, and the nucleus. Human PRDX5 is identified by virtue of the sequence homologies to yeast peroxisomal antioxidant enzyme PMP20. Biochemically, PRDX5 is a peroxidase that can use cytosolic or mitochondrial thioredoxins to reduce alkyl hydroperoxides or peroxynitrite with high rate constants in the 106 to 107 M−1s−1 range, whereas its reaction with hydrogen peroxide is more modest, in the 105 M−1s−1 range. So far, PRDX5 has been shown to be a cytoprotective antioxidant enzyme that inhibits endogenous or exogenous peroxide accumulation. Structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRDX1
Peroxiredoxin-1 is a protein that in humans is encoded by the ''PRDX1'' gene. Function This gene encodes a member of the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. The encoded protein may play an antioxidant protective role in cells, and may contribute to the antiviral activity of CD8(+) T-cells. This protein may have a proliferative effect and play a role in cancer development or progression. Three transcript variants encoding the same protein have been identified for this gene. Interactions Peroxiredoxin 1 has been shown to interact with PRDX4. A chemoproteomic approach has revealed that peroxiredoxin 1 is the main target of theonellasterone. Clinical significance As enzymes that combat oxidative stress, peroxiredoxins play an important role in health and disease. Peroxiredoxin 1 and peroxiredoxin 2 have been shown to be released by some cells when stimulated by LPS or TNF-alpha. The released peroxiredoxin can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxiredoxin 1
Peroxiredoxin-1 is a protein that in humans is encoded by the ''PRDX1'' gene. Function This gene encodes a member of the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. The encoded protein may play an antioxidant protective role in cells, and may contribute to the antiviral activity of CD8(+) T-cells. This protein may have a proliferative effect and play a role in cancer development or progression. Three transcript variants encoding the same protein have been identified for this gene. Interactions Peroxiredoxin 1 has been shown to interact with PRDX4. A chemoproteomic approach has revealed that peroxiredoxin 1 is the main target of theonellasterone. Clinical significance As enzymes that combat oxidative stress, peroxiredoxins play an important role in health and disease. Peroxiredoxin 1 and peroxiredoxin 2 have been shown to be released by some cells when stimulated by LPS or TNF-alpha. The released peroxiredoxin can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRDX3
Thioredoxin-dependent peroxide reductase, mitochondrial is an enzyme that in humans is encoded by the ''PRDX3'' gene. It is a member of the peroxiredoxin family of antioxidant enzymes. Function This gene encodes a protein with antioxidant function and is localized in the mitochondrion. This gene shows significant nucleotide sequence similarity to the gene coding for the C22 subunit of Salmonella typhimurium alkylhydroperoxide reductase. Expression of this gene product in ''E. coli'' deficient in the C22-subunit gene rescued resistance of the bacteria to alkylhydroperoxide. The human and mouse genes are highly conserved, and they map to the regions syntenic between mouse and human chromosomes. Sequence comparisons with recently cloned mammalian homologues suggest that these genes consist of a family that is responsible for regulation of cellular proliferation, differentiation, and antioxidant functions. Two transcript variants encoding two different isoforms have been found for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants, to prevent oxidation, and to foods to prevent spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress. The only dietary antioxidants are vitamins A, C, and E, but the term ''antioxidant'' has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro, with little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans. History As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxiredoxin 2
Peroxiredoxin-2 is a protein that in humans is encoded by the PRDX2 gene. PRDX2 encodes a member of the peroxiredoxin family of antioxidant enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...s, which reduce hydrogen peroxide and alkyl hydroperoxides. The encoded protein may play an antioxidant protective role in cells, and may contribute to the antiviral activity of CD8(+) T-cells. This protein may have a proliferative effect and play a role in cancer development or progression. The crystal structure of this protein has been resolved to 0.27 nm (= 2.7 angstroms). Transcript variants encoding distinct isoforms have been identified for this gene. References Further reading * * * * * * * * * * * * * * * * * * * * {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRDX2
Peroxiredoxin-2 is a protein that in humans is encoded by the PRDX2 gene. PRDX2 encodes a member of the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. The encoded protein may play an antioxidant protective role in cells, and may contribute to the antiviral activity of CD8(+) T-cells. This protein may have a proliferative effect and play a role in cancer development or progression. The crystal structure of this protein has been resolved to 0.27 nm (= 2.7 angstroms). Transcript variants encoding distinct isoforms have been identified for this gene. References Further reading * * * * * * * * * * * * * * * * * * * * {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfiredoxin
In enzymology, a sulfiredoxin () is an enzyme that catalyzes the chemical reaction :peroxiredoxin-(S-hydroxy-S-oxocysteine) + ATP + 2 R-SH \rightleftharpoons peroxiredoxin-(S-hydroxycysteine) + ADP + phosphate + R-S-S-R The 3 substrates of this enzyme are peroxiredoxin-(S-hydroxy-S-oxocysteine), ATP, and a thiol, whereas its 4 products are peroxiredoxin-(S-hydroxycysteine), ADP, phosphate, and a disulfide. This enzyme is involved in antioxidant metabolism by re-activating peroxiredoxins, which are a group of peroxidases, when these enzymes are inhibited by over-oxidation. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with other, known, acceptors. The systematic name of this enzyme class is peroxiredoxin-(S-hydroxy-S-oxocysteine):thiol oxidoreductase [ATP-hydrolysing; peroxiredoxin-(S-hydroxycysteine)-forming]. Other names in common use include Srx1, sulphiredoxin, and peroxiredoxin-(S-hydroxy-S-oxocysteine) re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRDX6
Peroxiredoxin-6 is a protein that in humans is encoded by the ''PRDX6'' gene. It is a member of the peroxiredoxin family of antioxidant enzymes. Function The protein encoded by this gene is a member of the thiol-specific antioxidant protein family. This protein is a bifunctional enzyme with two distinct active sites. It is involved in redox regulation of the cell; it can reduce H(2)O(2) and short chain organic, fatty acid, and phospholipid hydroperoxides. It may play a role in the regulation of phospholipid turnover as well as in protection against oxidative injury. Model organisms = Model organisms have been used in the study of PRDX6 function. A conditional knockout mouse line, called ''Prdx6tm1a(EUCOMM)Wtsi'' was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists — at the Wellcome Trust Sanger Institute. Male and female animals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRDX4
Peroxiredoxin-4 is a protein that in humans is encoded by the ''PRDX4'' gene. It is a member of the peroxiredoxin family of antioxidant enzymes. Function The protein encoded by this gene is an antioxidant enzyme of the peroxiredoxin family. The protein is localized to the cytoplasm. Peroxidases of the peroxiredoxin family reduce hydrogen peroxide and alkyl hydroperoxides to water and alcohol with the use of reducing equivalents derived from thiol-containing donor molecules. This protein has been found to play a regulatory role in the activation of the transcription factor NF-kappaB. Interactions PRDX4 has been shown to interact with Peroxiredoxin 1 Peroxiredoxin-1 is a protein that in humans is encoded by the ''PRDX1'' gene. Function This gene encodes a member of the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. The encoded protein m .... References Further reading * * * * * * * * {{gene- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxiredoxin Classification Index
PeroxiRedoxin classification indEX (PREX ) is a database of peroxiredoxins (Prxs) classified into one of six distinct subfamilies. Classification relies on the Deacon Active Site Profiling (DASP) approach that utilizes a position specific scoring matrix (PSSM) created from aligned signatures (built from sequence fragments surrounding active sites of structurally-characterized Prx group members) to search sequence databases. Searches of PREX for Prxs of interest can be conducted using protein annotation, accession number, PDB ID, organism name, or protein sequence (using BLAST) for Prx proteins extracted from January 2008, November 2010, or October 2011 versions of GenBank (over 8000 validated Prx sequences represented). Output includes the subfamily to which each classified Prx belongs, accession and GI numbers, genus and species, and the active site signature used for classification. The query sequence is also presented aligned with a select group of Prxs for manual evaluation an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationships ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
