Molecular defect in processing alpha-fucosidase in fucosidosis.

Abstract

In normal human skin fibroblasts, an enzymatically active 53,000-dalton form of alpha-fucosidase is processed to a 50,000-dalton mature form. Endoglycosidase-H treatment of [35S]methionine pulse-chase labelled material immunoprecipated with a polyclonal antibody to alpha-L-fucosidase (Andrews-Smith & Alhadeff, Biochim. Biophys. Acta 715: 90-96 (1982)) indicated the removal of a single N-linked oligosaccharide unit from both precursor and mature form of alpha-L-fucosidase. Tunicamycin pretreatment of normal fibroblasts indicated that no other N-linked oligosaccharide units were present. Studies on fibroblasts from patients with less than 5% of normal alpha-L-fucosidase activity (fucosidosis) showed 8 of 11 patients synthesized no detectable alpha-fucosidase protein whereas 2 synthesized normal amounts of 53,000 dalton precursor, none of the mature 50,000 dalton form was detectable and one contained small amounts of cross-reacting material. This is the first evidence for processing of alpha-L-fucosidase in cells and the first precise evidence of a molecular defect in fucosidosis.

• Authors: K Johnson, G Dawson
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 133 Issue 1 Pg. 90-7 (Nov 27 1985) ISSN: 0006-291X [Print] United States
• PMID: 4074382 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Oligosaccharides
• alpha-L-Fucosidase

Topics

• Cells, Cultured
• Cross Reactions
• Fibroblasts (enzymology)
• Fucosidosis (enzymology)
• Humans
• Molecular Weight
• Oligosaccharides (analysis)
• Skin (enzymology)
• alpha-L-Fucosidase (analysis, biosynthesis, immunology)