Sandbox Reserved 322: Difference between revisions
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[[Image:Arginases_homotrimer.jpg|thumb|left|300px|Figure 1: Liver arginase illustrating that the general homotrimeric strucutre of arginase<ref name="Homotrimer">accessed April 3,2011: http://en.wikipedia.org/wiki/Arginase.</ref>.]] | [[Image:Arginases_homotrimer.jpg|thumb|left|300px|Figure 1: Liver arginase illustrating that the general homotrimeric strucutre of arginase<ref name="Homotrimer">accessed April 3,2011: http://en.wikipedia.org/wiki/Arginase.</ref>.]] | ||
Arginase is a 105 kD homotrimeric metallo-protein, as shown in figure 1, and catalysis the hydrolysis of arginine to ornithine and urea by means of a binuclear spin-coupled Mn<sup>2+</sup> cluster in the active site<ref name="a">PMID: 19456858 </ref>. Many organisms contain the enzyme arginase, for example ''Homo sapiens'' and ''Plasmodium falciparum'', a parasite that causes cerebral malaria<ref name="b">PMID: 20527960 </ref>. In humans there are two forms of arginases that have evolved with differing tissue distributions and sub-cellular locations in mammals<ref name="c">PMID: 15766238 </ref>. | Arginase is a 105 kD homotrimeric metallo-protein, as shown in figure 1, and catalysis the hydrolysis of arginine to ornithine and urea by means of a binuclear spin-coupled Mn<sup>2+</sup> cluster in the active site<ref name="a">PMID: 19456858 </ref>. Many organisms contain the enzyme arginase, for example ''Homo sapiens'' and [http://en.wikipedia.org/wiki/Plasmodium_falciparum ''Plasmodium falciparum''], a parasite that causes cerebral malaria<ref name="b">PMID: 20527960 </ref>. In humans there are two forms of arginases that have evolved with differing tissue distributions and sub-cellular locations in mammals<ref name="c">PMID: 15766238 </ref>. | ||
The two types of arginase is found in mammalian, are arginase I (hAI) and arginases II (hAII)<ref name="c"/>. Arginase I is found predominantly in the liver, where it catalyzes the final cytosolic step of the urea cycle<ref name="c"/>. Arginases II is a mitochondrial enzyme that does not appear to function in the urea cycle and is more widely disturbed in numerous tissues, for example kidney, brains, skeletal muscle, mammary gland and penile corpus cavernosum<ref name="c"/>. Recent studies show that ''Plasmodium falciparum'' arginase (PFA) plays a role in systemic depletion of arginine levels, which in turn has been associated with human cerebral malaria pathogenesis<ref name="a"/>. In addition the arginase fold is part of the [http://en.wikipedia.org/wiki/Ureohydrolase ureohydrolase] superfamily, which also includes agmatinase, histone de-acetylase and acetylpolyamine amidohydrolase<ref name="a"/>. | The two types of arginase is found in mammalian, are arginase I (hAI) and arginases II (hAII)<ref name="c"/>. Arginase I is found predominantly in the liver, where it catalyzes the final cytosolic step of the urea cycle<ref name="c"/>. Arginases II is a mitochondrial enzyme that does not appear to function in the urea cycle and is more widely disturbed in numerous tissues, for example kidney, brains, skeletal muscle, mammary gland and penile corpus cavernosum<ref name="c"/>. Recent studies show that ''Plasmodium falciparum'' arginase (PFA) plays a role in systemic depletion of arginine levels, which in turn has been associated with human cerebral malaria pathogenesis<ref name="a"/>. In addition the arginase fold is part of the [http://en.wikipedia.org/wiki/Ureohydrolase ureohydrolase] superfamily, which also includes agmatinase, histone de-acetylase and acetylpolyamine amidohydrolase<ref name="a"/>. | ||