Expression and functional characterization of human mutant sulfamidase in insect cells

Magda Montfort, Elena Garrido, John J. Hopwood, Daniel Grinberg, Amparo Chabás, Lluïsa Vilageliu

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7 Citations (Scopus)


Mucopolysaccharidosis IIIA (MPS IIIA; Sanfilippo syndrome) is an autosomal recessive lysosomal disorder caused by the deficiency of sulfamidase (EC, required for the degradation of the mucopolysaccharide heparan sulfate. The molecular defects of 26 unrelated Spanish MPS IIIA patients were recently reported by our group. Here we describe the heterologous expression, using a baculovirus system, of the cDNAs corresponding to eight out of the 14 mutant alleles present in this patient group and the characterization of the corresponding mutant enzymes. In particular, we expressed the following alleles: p.S66W, p.R74H, p.Q85R, p.R206P, p.L386R, p.R433W, p.R433Q, and c.1079delC (previously named as c.1091delC), and the two variants of the polymorphism p.R456H. The expression of the mutant alleles and the characterization of the corresponding enzymes revealed that their activity was severely compromised. Only mutations p.S66W and p.R206P retained low levels of residual activity. However, Western blot analysis showed in all cases the presence of the expected two forms of the sulfamidase, the precursor and the mature proteins, indicating a normal processing of the mutant enzyme.

Original languageEnglish
Pages (from-to)246-251
Number of pages6
JournalMolecular Genetics and Metabolism
Issue number3
Publication statusPublished or Issued - Nov 2004


  • Bac-to-bac baculovirus expression system
  • Heparan N-sulfatase
  • Mucopolysaccharidosis IIIA
  • Sanfilippo syndrome
  • Sulfamidase
  • Transient expression

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Endocrinology

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