iduronidase, α-L- | |
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Identifiers | |
Symbol | IDUA |
Entrez | 3425 |
HUGO | 5391 |
OMIM | 252800 |
RefSeq | NM_000203 |
UniProt | P35475 |
Other data | |
EC number | 3.2.1.76 |
Locus | Chr. 4 p16.3 |
Iduronidase (EC 3.2.1.76, L-iduronidase, alpha-L-iduronidase, laronidase) is an enzyme with the systematic name glycosaminoglycan alpha-L-iduronohydrolase. This enzyme catalyses the hydrolysis of unsulfated alpha-L-iduronosidic linkages in dermatan sulfate.
It is a glycoprotein enzyme found in the lysosomes of cells. It is involved in the degeneration of glycosaminoglycans such as dermatan sulfate and heparan sulfate. The enzyme acts by hydrolyzing the terminal alpha-L-induronic acid residues of these molecules, degrading them. The protein is reported as having a mass of approximately 83 kilodaltons.
A deficiency in the IDUA protein is associated with mucopolysaccharidoses (MPS). MPS, a type of lysosomal storage disease, is typed I through VII. Type I is known as Hurler syndrome and type I,S is known as Scheie syndrome, which has a milder prognosis compared to Hurler's. In this syndrome, glycosaminoglycans accumulate in the lysosomes and cause substantial disease in many different tissues of the body. IDUA mutations result in the MPS 1 phenotype, which is inherited in an autosomal recessive fashion. The defective alpha-L-iduronidase results in an accumulation of heparan and dermatan sulfate within phagocytes, endothelium, smooth muscle cells, neurons, and fibroblasts. Under electron microscopy these structures present as laminated structures called Zebra bodies.
Prenatal diagnosis of this enzyme deficiency is possible.
Aldurazyme is the name of the commercialized variant of the enzyme Iduronidase, which hydrolyzes the alpha-L-iduronic acid residues of dermatan sulfate and heparin sulfate. Produced in Chinese hamster ovaries by recombinant DNA technology, Aldurazyme is the manufactured by BioMarin Pharmaceutical Inc. and distributed by Genzyme Corporation (a subsidiary of Sanofi). Aldurazyme is administered as a slow intravenous infusion. The recombinant enzyme is 628 amino acids in length with 6 N-linked oligosaccharide modification sites and two oligosaccharide chains terminating in mannose sugars.