Alpha-L-Iduronidase encoded by the IDUA gene is an important enzyme required for the lysosomal degradation of glycosaminoglycans (GAGs). It hydrolyzes the non-reducing terminal alpha-L-iduronic acid residues in GAGs including dermatan sulfate and heparan sulfate. Mutations in IDUA that result in enzymatic deficiency lead to the autosomal recessive disease mucopolysaccharidosis type I (MPS I) (1). MPS I causes progressive cellular, tissue and organ damage, and several clinical studies using enzyme replacement therapy have shown promising benefits (2). The purified rhIDUA has an N-terminal sequence of T26EAPHLVQVD. The 638 amino acid residue rhIDUA predicts a molecular mass of 71kD, and migrates as an ~83kD protein by SDS-PAGE under reducing conditions. Recombinant protein corresponding to Ala26-Pro653 (Ala26Thr) with a C-terminal 10-His tag expressed in NSO cells (AAA81589). Molecular Mass: The purified rhIDUA has an N-terminal sequence of T26EAPHLVQVD. The 638 amino acid residue rhIDUA predicts a molecular mass of 71kD, and migrates as an approximately 83kD protein by SDS-PAGE under reducing conditions. Activity: Measured by its ability to cleave a fluorogenic substrate, 4-Methylumbelliferyl alpha-L-iduronide. Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
