Arginase, type II is an
arginase
Arginase (, ''arginine amidinase'', ''canavanase'', ''L-arginase'', ''arginine transamidinase'') is a manganese-containing enzyme. The reaction catalyzed by this enzyme is:
: arginine + H2O → ornithine + urea
It is the final enzyme of the ure ...
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ARG2
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
Arginase
Arginase (, ''arginine amidinase'', ''canavanase'', ''L-arginase'', ''arginine transamidinase'') is a manganese-containing enzyme. The reaction catalyzed by this enzyme is:
: arginine + H2O → ornithine + urea
It is the final enzyme of the ure ...
catalyzes the hydrolysis of
arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the am ...
to
ornithine
Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl.
Role in urea cycle
L-Ornithine is one of the produ ...
and
urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid.
Urea serves an important r ...
. At least two isoforms of mammalian arginase exists (
types I and II, this enzyme) which differ in their tissue distribution, subcellular localization, immunologic crossreactivity and physiologic function. The type II isoform encoded by this gene, is located in the mitochondria and expressed in extra-hepatic tissues, especially kidney. The physiologic role of this isoform is poorly understood; it is thought to play a role in
nitric oxide
Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its che ...
and
polyamine
A polyamine is an organic compound having more than two amino groups. Alkyl polyamines occur naturally, but some are synthetic. Alkylpolyamines are colorless, hygroscopic, and water soluble. Near neutral pH, they exist as the ammonium derivatives. ...
metabolism. Transcript variants of the type II gene resulting from the use of alternative
polyadenylation
Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In euk ...
sites have been described.
References
External links
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Further reading
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EC 3.5.1
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