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Structural study on mutant alpha-L-iduronidases: insight into mucopolysaccharidosis type I
Kanako Sugawara1, Seiji Saito2, Kazuki Ohno3,4
1Department of Analytical Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan.
Journal of Human Genetics
|March 15, 2008
Summary
Structural analysis of alpha-L-iduronidase (IDUA) mutations reveals distinct patterns correlating with mucopolysaccharidosis type I (MPS I) severity. These findings aid in predicting clinical outcomes for MPS I patients.
Area of Science:
- Biochemistry
- Structural Biology
- Genetics
Background:
- Mucopolysaccharidosis type I (MPS I) is a genetic disorder caused by mutations in the alpha-L-iduronidase (IDUA) gene.
- Understanding the structural basis of IDUA mutations is crucial for diagnosing and managing MPS I.
- Previous studies have identified numerous IDUA mutations linked to varying MPS I phenotypes.
Purpose of the Study:
- To elucidate the structural basis of different mucopolysaccharidosis type I (MPS I) phenotypes.
- To correlate structural changes in mutant alpha-L-iduronidases (IDUA) with disease severity.
- To assess the utility of structural analysis in predicting MPS I clinical outcomes.
Main Methods:
- Construction of structural models for 33 mutant alpha-L-iduronidase (IDUA) enzymes associated with MPS I.
- Analysis of structural changes using metrics such as the number of affected atoms, root-mean-square distance (RMSD), and solvent-accessible surface area (ASA).
- Comparative analysis of structural alterations between severe, intermediate, and attenuated MPS I groups.
Main Results:
- Severe MPS I mutations caused larger structural changes (more atoms affected, higher RMSD, less accessible residues) compared to attenuated MPS I mutations.
- Intermediate MPS I phenotypes showed intermediate values for affected atoms, RMSD, and ASA.
- Structural changes in severe MPS I were concentrated in the enzyme's core, while attenuated MPS I showed changes on the molecular surface.
Conclusions:
- Structural analysis of alpha-L-iduronidase (IDUA) provides insights into the molecular basis of mucopolysaccharidosis type I (MPS I) severity.
- Distinct structural alteration patterns correlate with severe versus attenuated MPS I phenotypes.
- IDUA structural analysis can potentially predict the clinical outcome of MPS I.
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