alpha-L-Iduronidase human

General description

α-L-Iduronidase (IDUA) is mapped to human chromosome 4p16.3. The mature IDUA protein is glycosylated and comprises triosephosphate isomerase (TIM) barrel domain, β-sandwich, helix-loop-helix region and an immunoglobin-like domain. α-L-Iduronidase is classified under glycoside hydrolase (GH) family 39.

Application

α-L-Iduronidase may be used for leukocyte assay in the study of a-L-Iduronidase deficiency in new born.

Biochem/physiol Actions

In lysosomal degradation process α-L-Iduronidase plays a crucial role. It hydrolyzes the non-reducing terminal α-L-iduronic acid residues in glycosaminoglycans (GAGs), including dermatan sulfate and heparan sulfate.

Mutation in the α-L-Iduronidase is implicated in Mucopolysaccharidosis I (MPS I) . This enzyme defect leades to accumulation of dermatan and heparan sulfate . MPS I pathophysiology is accompanied with deformation of the skull, mental retardation and hernias.

Catalyzes the hydrolysis of unsulfated α-L-iduronosidic linkages in dermatan sulfate

Physical properties

Expressed as C-terminal histine-tagged protein (residues 1-653) with a caluclated molecular mass of 71 kDa migrating at ~83 kDa under SDS-PAGE reducing conditions.

Unit Definition

One unit will produce 1 picomole of 4-methylumbelliferone from 4-methylumbelliferyl-α-L-iduronide per minute at pH 3.5 at 25 °C.

Physical form

Supplied as a solution in 40 mM sodium acetate , 400 mM NaCl and 20% (v/v) glycerol, pH 5.0