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Information about Oxidoreductases

In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule (the reductant, also called the hydrogen acceptor or electron donor) to another (the oxidant, also called the hydrogen donor or electron acceptor). For example, an enzyme that catalyzed this reaction would be an oxidoreductase:

A– + B → A + B–


In this example, A is the reductant (electron donor) and B is the oxidant (electron acceptor).

In biochemical reactions, the redox reactions are sometimes more difficult to see, such as this reaction from glycolysis:

Pi + glyceraldehyde-3-phosphate + NAD+ → NADH + H+ + 1,3-bisphosphoglycerate


In this reaction, NAD+ is the oxidant (electron acceptor), and glyceraldehyde-3-phosphate is the reductant (electron donor).

Nomenclature

Proper names of oxidoreductases are formed as "donor:acceptor oxidoreductase." However, other names are much more common. The common name is "donor dehydrogenase" when possible, such as glyceraldehyde-3-phosphate dehydrogenase for the second reaction above. Common names are also sometimes formed as "acceptor reductase", such as NAD+ reductase. "Donor oxidase" is a special case where O2 is the acceptor.

Classification

Oxidoreductases are classified as EC 1 in the EC number classification of enzymes. Oxidoreductases can be further classified into 22 subclasses:
  • includes oxidoreductases that act on the CH-OH group of donors (alcohol oxidoreductases)
  • includes oxidoreductases that act on the aldehyde or oxo group of donors
  • includes oxidoreductases that act on the CH-CH group of donors (CH-CH oxidoreductases)
  • includes oxidoreductases that act on the CH-NH2 group of donors (Amino acid oxidoreductases, Monoamine oxidase)
  • includes oxidoreductases that act on CH-NH group of donors
  • includes oxidoreductases that act on NADH or NADPH
  • includes oxidoreductases that act on other nitrogenous compounds as donors
  • includes oxidoreductases that act on a sulfur group of donors
  • includes oxidoreductases that act on a heme group of donors
  • includes oxidoreductases that act on diphenols and related substances as donors
  • includes oxidoreductases that act on peroxide as an acceptor (peroxidases)
  • includes oxidoreductases that act on hydrogen as donors
  • includes oxidoreductases that act on single donors with incorporation of molecular oxygen (oxygenases)
  • includes oxidoreductases that act on paired donors with incorporation of molecular oxygen
  • includes oxidoreductases that act on superoxide radicals as acceptors
  • includes oxidoreductases that oxidize metal ions
  • includes oxidoreductases that act on CH or CH2 groups
  • includes oxidoreductases that act on iron-sulfur proteins as donors
  • includes oxidoreductases that act on reduced flavodoxin as a donor
  • includes oxidoreductases that act on phosphorus or arsenic in donors
  • includes oxidoreductases that act on X-H and Y-H to form an X-Y bond
  • includes other oxidoreductases

See also

External link

 •  • [ e]
Proteins: enzymes
TopicsActive site - Allosteric regulation - Binding site - Catalytically perfect enzyme - Coenzyme - Cofactor - Cooperativity - EC number
Enzyme catalysis - Enzyme inhibitor - Enzyme kinetics - Lineweaver-Burk plot - Michaelis-Menten kinetics - List of enzymes
TypesEC1 Oxidoreductases/list - EC2 Transferases/list - EC3 Hydrolases/list - EC4 Lyases/list - EC5 Isomerases/list - EC6 Ligases/list
 •  • [ e]
Oxidoreductases: alcohol oxidoreductases (EC 1.1)
1.1.1 NAD/NADP acceptor Carbohydrate dehydrogenases - Alcohol dehydrogenase - Glycerol-3-phosphate dehydrogenase - L-xylulose reductase - Aldose reductase - Lactate dehydrogenase - 3-Hydroxyacyl CoA dehydrogenase - Malate dehydrogenase - Isocitrate dehydrogenase - Phosphogluconate dehydrogenase - Glucose-6-phosphate dehydrogenase - HMG-CoA reductase - Β-Ketoacyl ACP reductase - Hydroxysteroid dehydrogenase: 11 Beta (, ) - 3 Beta (3-beta-HSD) - 17 Beta - Carnitine dehydrogenase - Beta-hydroxybutyryl-CoA dehydrogenase - IMP dehydrogenase - DXP reductoisomerase
1.1.3 oxygen acceptor Glucose oxidase - L-gulonolactone oxidase - Xanthine oxidase
 •  • [ e]
Aldehyde/oxo oxidoreductases (EC 1.2)
1.2.1 - NAD or NADP acceptorAldehyde dehydrogenase - Acetaldehyde dehydrogenase (ALDH2) - Glyceraldehyde 3-phosphate dehydrogenase - Long-chain-aldehyde dehydrogenase
1.2.4 - disulfide acceptorOxoglutarate dehydrogenase - Pyruvate dehydrogenase - Branched-chain alpha-keto acid dehydrogenase complex
 •  • [ e]
Oxidoreductases: CH-CH oxidoreductases (EC 1.3)
1.3.1. NAD/NADP acceptorEnoyl-acyl carrier protein reductase/Enoyl ACP reductase - 7-Dehydrocholesterol reductase - Biliverdin reductase - 2,4 Dienoyl-CoA reductase
1.3.3. Oxygen acceptorDihydroorotate dehydrogenase - Coproporphyrinogen III oxidase - Protoporphyrinogen oxidase -
1.3.5. QuinoneSuccinate - coenzyme Q reductase
1.3.99. Other acceptorsFumarate reductase - Butyryl CoA dehydrogenase - Acyl CoA dehydrogenase - 5-alpha reductase - Glutaryl-CoA dehydrogenase - Isovaleryl coenzyme A dehydrogenase
 •  • [ e]
CH-NH2 oxidoreductases (EC 1.4) - primarily amino acid oxidoreductases
1.4.1 - NAD/NADP acceptorGlutamate dehydrogenase (GLUD1)
1.4.3 - oxygen acceptorD-amino acid oxidase - Amine oxidase - Lysyl oxidase - Monoamine oxidase
1.4.4 - disulfide acceptorGlycine decarboxylase complex
1.4.99 - other acceptorsD-amino acid dehydrogenase - Amine dehydrogenase
 •  • [ e]
CH-NH oxidoreductases (EC 1.5)
1.5.1 - NAD or NADP acceptorDihydrofolate reductase - Saccharopine dehydrogenase - Methylenetetrahydrofolate reductase
1.5.3 - oxygen acceptorDihydrobenzophenanthridine oxidase - Sarcosine oxidase
1.5.5 - quinone acceptorElectron-transferring-flavoprotein dehydrogenase
 •  • [ e]
NADH or NADPH oxidoreductases (EC 1.6)
Methemoglobin reductase - NADPH oxidase (P91-PHOX) - NADH dehydrogenase
 •  • [ e]
Oxidoreductases: nitrogenous donor (EC 1.7)
GMP reductase - Urate oxidase
 •  • [ e]
Oxidoreductases: sulfur oxidoreductases (EC 1.8)
Dihydrolipoamide dehydrogenase - Glutathione reductase - Thioredoxin reductase - Sulfite oxidase
 •  • [ e]
Diphenol family oxidoreductases (EC 1.10)
Coenzyme Q - cytochrome c reductase - Catechol oxidase - Laccase - Alternative oxidase
 •  • [ e]
Oxidoreductases: peroxidases (EC 1.11)
Catalase - Cytochrome c peroxidase - Eosinophil peroxidase - Glutathione peroxidase - Horseradish peroxidase - Lactoperoxidase - Myeloperoxidase - Thyroid peroxidase - Deiodinase (Tetraiodothyronine 5' deiodinase)
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Oxidoreductases: monooxygenases (EC 1.13)
1.13.11 - two atoms of oxygenCatechol dioxygenase - Homogentisate 1,2-dioxygenase - Cysteine dioxygenase - 4-Hydroxyphenylpyruvate dioxygenase - Indoleamine 2,3-dioxygenase - Lipoxygenase (5)
1.13.12 - one atom of oxygenFirefly luciferase
1.13.99 - otherInositol oxygenase
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Oxidoreductases: dioxygenases, including steroid hydroxylases (EC 1.14)
1.14.11 - 2-oxoglutarateProlyl hydroxylase - Lysyl hydroxylase
1.14.13 - NADH or NADPHFlavin-containing monooxygenase - Nitric oxide synthase - Cholesterol 7 alpha-hydroxylase - Methane monooxygenase - 3A4 -51A1
1.14.14 - reduced flavin or flavoprotein19A1 - 2D6 - 2E1
1.14.15 - reduced iron-sulfur protein11B1 - 11B2 - 11A1
1.14.16 - reduced pteridinePhenylalanine hydroxylase - Tyrosine hydroxylase - Tryptophan hydroxylase
1.14.17 - reduced ascorbateDopamine beta hydroxylase
1.14.18-19 - otherTyrosinase - Stearoyl-CoA desaturase-1
1.14.99 - miscellaneousCyclooxygenase - Heme oxygenase (HMOX1) - Squalene monooxygenase - 17A1 - 21A2
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Other oxidoreductases (EC 1.15-1.18)
1.15 - Acting on superoxide as acceptorSuperoxide dismutase
1.16 - Oxidizing metal ionsCeruloplasmin
1.17 - Acting on CH or CH2 groupsXanthine oxidase - Ribonucleotide reductase
1.18 - Acting on iron-sulfur proteins as donorsNitrogenase
Biochemistry is the study of the chemical processes in living organisms.[1] The word "biochemistry" comes from the Greek word βιοχημεία biochēmeia, which means "the chemistry of life.
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Enzymes are proteins that catalyze (i.e. accelerate) chemical reactions.[1] In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, the products.
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Electron

Theoretical estimates of the electron density for the first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density
Composition: Elementary particle
Family: Fermion
Group: Lepton
Generation: First
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A reducing agent (also called a reductant or reducer) is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species.
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oxidizing agent (also called an oxidant or oxidizer) is
  1. A chemical compound that readily transfers oxygen atoms or
  2. A substance that gains electrons in a redox chemical reaction.
The former definition is not applicable to what most people read about.
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Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed.

This can be either a simple redox process such as the oxidation of carbon to yield carbon dioxide, or the
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Embden-Meyerhof pathway, initially explained by Gustav Embden and Otto Meyerhof. The term can be taken to include alternative pathways, such as the Entner-Doudoroff Pathway. However, glycolysis will be used here as a synonym for the Embden-Meyerhof pathway.
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A dehydrogenase is an enzyme that oxidizes a substrate by transferring one or more protons and a pair of electrons to an acceptor, usually NAD/NADP or a flavin coenzyme such as FAD or FMN.
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An oxidase is any enzyme that catalyzes an oxidation/reduction reaction involving molecular oxygen (O2) as the electron acceptor. In these reactions, oxygen is reduced to water (H2O) or hydrogen peroxide (H2O2).
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2, −1
(neutral oxide)
Electronegativity 3.44 (Pauling scale)
Ionization energies
(more) 1st: 1313.9 kJmol−1
2nd: 3388.3 kJmol−1
3rd: 5300.5 kJmol−1

Atomic radius 60 pm
Atomic radius (calc.
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Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. As a system of enzyme nomenclature, every EC number is associated with a recommended name for the respective enzyme.
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Alcohol oxidoreductases are oxidoreductase enzymes which act upon an alcohol functional group.

They are classified under "1.1" in the EC number numbering system.

External links

  • MeSH Alcohol+oxidoreductases

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aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom which is bonded to a hydrogen atom and double-bonded to an oxygen atom (chemical formula O=CH-), is called the aldehyde group.
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CH-CH oxidoreductases are oxidoreductase enzymes which convert single bonds and double bonds between two carbon atoms. They are classified under EC number 1.3.

One example is 5-alpha reductase:

Testosterone.

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Amino acid oxidoreductases are oxidoreductases, a type of enzyme, that act upon amino acids.

They constitute the majority of enzymes classified under EC number 1.4, with most of the remainder being monoamine oxidases.
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Identifiers
Symbol MAOB

Entrez 4129
HUGO 6834
OMIM 309860

RefSeq NM_000898
UniProt P27338
Other data
EC number 1.4.3.4
Locus Chr. X p11.4-p11.3 Monoamine oxidases (singular abbreviation MAO) (EC 1.4.3.
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6
(strongly acidic oxide)
Electronegativity 2.58 (Pauling scale)
Ionization energies
(more) 1st: 999.6 kJmol−1
2nd: 2252 kJmol−1
3rd: 3357 kJmol−1

Atomic radius 100 pm
Atomic radius (calc.
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A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. Not all porphyrins contain iron, but a substantial fraction of porphyrin-containing metalloproteins have heme as
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Benzenediols or dihydroxybenzenes are aromatic chemical compounds and polyphenols in which two hydroxyl groups are substituted onto a benzene ring. Because they have at least one hydroxyl group covalently bonded directly to a carbon atom in a benzene ring, they are in a
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A peroxide is a compound containing an oxygen-oxygen single bond. The simplest stable peroxide is hydrogen peroxide. Superoxides, dioxygenyls, ozones and ozonides compound are considered separately.
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Peroxidases (EC number 1.11.1.x ) are a large family of enzymes. A majority of peroxidase protein sequences can be found in the PeroxiBase database. Peroxidases typically catalyze a reaction of the form:

ROOR' + electron donor (2 e-) + 2H+

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An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O2 (as in air) to it. The oxygenases form a class of oxidoreductases; their EC number is EC 1.13 or EC 1.14.
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Superoxide is the anion O2−. It is important as the product of the one-electron reduction of dioxygen, which occurs widely in nature.[1] With one unpaired electron, the superoxide ion is a free radical, and, like dioxygen, it is paramagnetic.
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Flavodoxin is a bacterial protein that includes flavin mononucleotide. It contains five beta sheets.

External links

  • MeSH Flavodoxin
  • "The crossovers of flavodoxin" at virginia.edu
  • Diagram at tran.wau.nl
  • Diagram at ohio-state.

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5, 4
(mildly acidic oxide)
Electronegativity 2.19 (Pauling scale)
Ionization energies
(more) 1st: 1011.8 kJmol−1
2nd: 1907 kJmol−1
3rd: 2914.1 kJmol−1

Atomic radius 100 pm
Atomic radius (calc.
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3, 5
(mildly acidic oxide)
Electronegativity 2.18 (scale Pauling)
Ionization energies
(more) 1st: 947.0 kJmol−1
2nd: 1798 kJmol−1
3rd: 2735 kJmol−1
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This article is a list of enzymes, sorted by their respective sub-categories and EC number.

See also:
  • List of EC numbers
  • List of EC numbers (EC 1)
  • List of EC numbers (EC 2)
  • List of EC numbers (EC 3)
  • List of EC numbers (EC 4)
  • List of EC numbers (EC 5)

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Hydroxylation is any chemical process that introduces one or more hydroxyl groups (-OH) into a compound (or radical) thereby oxidizing it. In biochemistry, hydroxylation reactions are often facilitated by enzymes called hydroxylases.
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London Hospital Medical College)
1843 (Medical College of St Bartholomew's Hospital)
1882 (Westfield College)
1885 (Queen Mary College)
1989 (merger of Queen Mary & Westfield)
1995 (medical schools merge with QMW)
Type Public
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Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
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