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L-gulonolactone oxidase

 

 
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L-gulonolactone oxidase
 
 
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L-gulonolactone oxidase (EC
EC number

The Enzyme Commission number is a numbering scheme scheme for enzymes, based on the chemical reactions they catalysis.As a system of enzyme nomenclature, every EC number is associated with a recommended name for the respective enzyme....
 ) is an enzyme
Enzyme

Enzymes are biomolecules that catalysis chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are called Substrate , and the enzyme converts them into different molecules, the products....
 that catalyzes the reaction
Chemical reaction

A chemical reaction is a process that always results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants....
 of D-glucuronolactone
Glucuronolactone

Glucuronolactone is a naturally occurring chemical produced by the metabolism of glucose in the human liver. It is an important structural component of nearly all connective tissues....
 (also known as L-gulono-1,4-lactone) with oxygen
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
 to L-xylo-hex-3-gulonolactone and hydrogen peroxide
Hydrogen peroxide

Hydrogen peroxide is a very pale blue liquid which appears colorless in a dilute solution, slightly more viscous than water. It is a weak acid....
. It uses FAD as a cofactor
Cofactor

Cofactor may refer to any of the following:* Cofactor The signed minor of a matrix* Minor as an alternative name for the determinant of a smaller Matrix than that which it describes...
. The L-xylo-hex-3-gulonolactone (2-keto-gulono-gamma-lactone) is able to spontaneously convert to hexuronic acid (ascorbic acid
Ascorbic acid

Ascorbic acid is a sugar acid with antioxidant properties. Its appearance is white to light-yellow crystals or powder. It is water-soluble. The L-enantiomer of ascorbic acid is commonly known as vitamin C....
), without enzymatic action.

The CAS number for this enzyme is

Gulonolactone oxidase deficiency
The non-functional gulonolactone oxidase pseudogene (GULOP) was mapped to human chromosome
Chromosome

A chromosome is an organized structure of DNA and protein that is found in Cell . A chromosome is a single piece of DNA that contains many genes, regulatory sequence and other genetic sequence....
 8p21
Chromosome 8 (human)

Chromosome 8 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 8 spans about 145 million base pairs and represents between 4.5 and 5.0% of the total DNA in cell ....
 that corresponds to an evolutionarily conserved segment on either porcine chromosome 4 (SSC4) or 14 (SSC14).






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L-gulonolactone oxidase (EC
EC number

The Enzyme Commission number is a numbering scheme scheme for enzymes, based on the chemical reactions they catalysis.As a system of enzyme nomenclature, every EC number is associated with a recommended name for the respective enzyme....
 ) is an enzyme
Enzyme

Enzymes are biomolecules that catalysis chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are called Substrate , and the enzyme converts them into different molecules, the products....
 that catalyzes the reaction
Chemical reaction

A chemical reaction is a process that always results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants....
 of D-glucuronolactone
Glucuronolactone

Glucuronolactone is a naturally occurring chemical produced by the metabolism of glucose in the human liver. It is an important structural component of nearly all connective tissues....
 (also known as L-gulono-1,4-lactone) with oxygen
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
 to L-xylo-hex-3-gulonolactone and hydrogen peroxide
Hydrogen peroxide

Hydrogen peroxide is a very pale blue liquid which appears colorless in a dilute solution, slightly more viscous than water. It is a weak acid....
. It uses FAD as a cofactor
Cofactor

Cofactor may refer to any of the following:* Cofactor The signed minor of a matrix* Minor as an alternative name for the determinant of a smaller Matrix than that which it describes...
. The L-xylo-hex-3-gulonolactone (2-keto-gulono-gamma-lactone) is able to spontaneously convert to hexuronic acid (ascorbic acid
Ascorbic acid

Ascorbic acid is a sugar acid with antioxidant properties. Its appearance is white to light-yellow crystals or powder. It is water-soluble. The L-enantiomer of ascorbic acid is commonly known as vitamin C....
), without enzymatic action.

The CAS number for this enzyme is

Gulonolactone oxidase deficiency


The non-functional gulonolactone oxidase pseudogene (GULOP) was mapped to human chromosome
Chromosome

A chromosome is an organized structure of DNA and protein that is found in Cell . A chromosome is a single piece of DNA that contains many genes, regulatory sequence and other genetic sequence....
 8p21
Chromosome 8 (human)

Chromosome 8 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 8 spans about 145 million base pairs and represents between 4.5 and 5.0% of the total DNA in cell ....
 that corresponds to an evolutionarily conserved segment on either porcine chromosome 4 (SSC4) or 14 (SSC14). GULO produces the precursor to ascorbic acid
Ascorbic acid

Ascorbic acid is a sugar acid with antioxidant properties. Its appearance is white to light-yellow crystals or powder. It is water-soluble. The L-enantiomer of ascorbic acid is commonly known as vitamin C....
, which spontaneously converts to the vitamin ("vitamin C
Vitamin C

Vitamin C or ascorbic acid is an essential nutrient for humans, a large number of simian species, a small number of other mammalian species , a few species of birds, and some fish....
").

The loss of activity of the gene for L-gulonolactone oxidase
L-gulonolactone oxidase

L-gulonolactone oxidase is an enzyme that catalyzes the chemical reaction of D-glucuronolactone with oxygen to L-xylo-hex-3-gulonolactone and hydrogen peroxide....
 (GULO) has occurred separately in the history of several species. The loss of this enzyme activity is responsible of inability of guinea pig
Guinea pig

The guinea pig is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not pigs, nor do they come from Guinea ....
s to enzymatically synthesize vitamin C, but this event happened independently of the loss in the haplorrhini
Haplorrhini

The haplorrhines, the "dry-nosed" primates , are members of the Haplorrhini Cladistics: the prosimian tarsiers and all of the true simians ....
 suborder of primates, including humans. The remains of this non-functional gene with many mutations, is however still present in the genome of the guinea pigs and in humans. The function of GULO appears to have been lost several times, and possibly re-acquired, in several lines of passerine
Passerine

A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders:...
 birds, where ability to make vitamin C varies from species to species. In addition, GULO activity has also been lost in all types of bats, regardless of diet.

Loss of GULO activity in the primate
Primate

A primate is a member of the biological order Primates , the group that contains lemurs, the Aye-aye, Lorisidaes, galagos, tarsiers, monkeys, and apes, with the last category including humans....
 order occurred about 63 million years ago, at about the time it split into the suborders haplorrhini
Haplorrhini

The haplorrhines, the "dry-nosed" primates , are members of the Haplorrhini Cladistics: the prosimian tarsiers and all of the true simians ....
 (which lost the enzyme activity) and the more primitive strepsirrhini
Strepsirrhini

The clade Strepsirrhini is one of the two suborders of primates. One of the most distinguishing characteristic of these 118 species is their wet noses, and it is this feature for which the grouping is named....
 (which retained it). The haplorrhini ("simple nosed") primates, which cannot make vitamin C enzymatically, include the tarsiers and the simians (apes, monkeys and humans). The suborder strepsirrhini (bent or wet nosed prosimians) which are still able to make vitamin C enzymatically, include loris
Loris

Loris is the common name for the strepsirrhine primates of the subfamily Lorinae in family Lorisidae. Loris is one genus in this subfamily and represents the slender lorises, while Nycticebus is the genus for the slow lorises....
es, galago
Galago

Galagos, also known as bushbabies, bush babies or nagapies , are small, nocturnal primates native to continental Africa, and make up the family Galagidae ....
s, potto
Potto

The Potto is a strepsirrhine primate from the Lorisidae family. It is the only species in genus Perodicticus. The name "Potto" possibly comes from the African word "pata", which means tailless ape....
s, and to some extent, lemur
Lemur

Lemurs make up the infraorder Lemuriformes and are members of a group of primates known as prosimians. The term "lemur" is derived from the Latin word lemures, meaning "spirits of the night" or "ghosts"....
s. .

L-gulonolactone oxidase deficiency is called "hypoascorbemia" and is described by OMIM (Online Mendelian Inheritance in Man) as "a public inborn error of metabolism", as it affects all humans. There exists a wide discrepancy between the amounts of ascorbic acid other primates consume and what is recommended as "reference intakes" for humans.

See also

  • Vitamin C
    Vitamin C

    Vitamin C or ascorbic acid is an essential nutrient for humans, a large number of simian species, a small number of other mammalian species , a few species of birds, and some fish....
  • ascorbic acid
    Ascorbic acid

    Ascorbic acid is a sugar acid with antioxidant properties. Its appearance is white to light-yellow crystals or powder. It is water-soluble. The L-enantiomer of ascorbic acid is commonly known as vitamin C....
  • Oxidoreductase
    Oxidoreductase

    In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another ....
  • scurvy
    Scurvy

    Scurvy is a disease resulting from a deficiency of vitamin C, which is required for the synthesis of collagen in humans. The chemical name for vitamin C, ascorbic acid, is derived from the Latin name of scurvy, scorbutus....