Iduronate 2-sulfatase (EC 3.1.6.13; systematic name
L-iduronate-2-sulfate 2-sulfohydrolase) is a
sulfatase
Sulfatases are enzymes of the esterase class that catalyze the hydrolysis of sulfate esters. These may be found on a range of substrates, including steroids, carbohydrates and proteins. Sulfate esters may be formed from various alcohols and amin ...
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 ...
associated with
Hunter syndrome
Hunter syndrome, or mucopolysaccharidosis type II (MPS II), is a rare genetic disorder in which large sugar molecules called glycosaminoglycans (or GAGs or mucopolysaccharides) build up in body tissues. It is a form of lysosomal storage disease. ...
.
It catalyses hydrolysis of the 2-sulfate groups of the
L-iduronate 2-sulfate units of dermatan sulfate, heparan sulfate and heparin.
Function
Iduronate 2-sulfatase is required for the lysosomal degradation of
heparan sulfate
Heparan sulfate (HS) is a linear polysaccharide found in all animal tissues. It occurs as a proteoglycan (HSPG, i.e. Heparan Sulfate ProteoGlycan) in which two or three HS chains are attached in close proximity to cell surface or extracellular ma ...
and
dermatan sulfate
Dermatan sulfate is a glycosaminoglycan (formerly called a mucopolysaccharide) found mostly in skin, but also in blood vessels, heart valves, tendons, and lungs.
It is also referred to as chondroitin sulfate B, although it is no longer class ...
. Mutations in this X-chromosome gene that result in enzymatic deficiency lead to the sex-linked
mucopolysaccharidosis
Mucopolysaccharidoses are a group of metabolic disorders caused by the absence or malfunctioning of lysosomal enzymes needed to break down molecules called glycosaminoglycans (GAGs). These long chains of sugar carbohydrates occur within the cel ...
type II, also known as Hunter syndrome. At least 174 disease-causing mutations in this gene have been discovered.
Iduronate-2-sulfatase has a strong
sequence homology
Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a ...
with human
arylsulfatase
Arylsulfatase (EC 3.1.6.1, sulfatase, nitrocatechol sulfatase, phenolsulfatase, phenylsulfatase, ''p''-nitrophenyl sulfatase, arylsulfohydrolase, 4-methylumbelliferyl sulfatase, estrogen sulfatase) is a type of sulfatase enzyme with systematic na ...
s A, B, and C, and human
glucosamine-6-sulfatase. A splice variant of this gene has been described.
See also
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Idursulfase
Idursulfase (brand name Elaprase), manufactured by Takeda Pharmaceutical Company, Takeda, is a drug used to treat Hunter syndrome (also called Mucopolysaccharoidosis#MPS II, MPS-II). It is a purified form of the lysosome, lysosomal enzyme iduronate ...
References
Further reading
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External links
GeneReviews/NIH/NCBI/UW entry on Mucopolysaccharidosis Type II
EC 3.1.6
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