| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1998: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
1) Sulfatases, including GALNS(N-acetylgalactosamine-6-sulfate sulfatase), are members of a highly conserved gene family sharing an extensive sequence homology. Thus, a tertiary structural model of human GALNS was constructed from the X-ray crystal structure of N-acetylgalactosamine-4-sulfatase (4S) and arylsulfatase A (ASA), using homology modeling. Based on the GALNS structural model, 32 missense mutations were investigated. Consequently, we propose that there are at least three different reasons for the severe phenotype; (a) destruction of the hydrophobic core or modification of the packing (b) removal of a salt-bridge to destabilize the entire conformation (c) modification of the active site. In contrast, mild mutations were mostly located on the surface of the GALNS protein. These studies shed further light on the genotype/phenotype correlation of MPS IVA and structure/function relationship in the sulfatase family.
2) Nearly 180 patients with MPS IVA have been supplied by international cooperative study, 90 various kinds of gene mutations have been defined. Especially, four different common mutations, I113F, a double gene deletion, G301C, R386C had been identified in respective specific populations. We also found other common mutations D60N in Finnish patients. These findings were useful information to determine the origin of mutations and the genetic background of these patients.
3) Genomic DNA for mouse Galns was cloned and characterized to prepare the animal model with MPS IVA.
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