The 1.9 Astroms Structure of Human α-N-Acetylgalactosaminidase: The Molecular Basis of Schindler and Kanzaki Diseases
?-N-acetylgalactosaminidase (?-NAGAL; E.C. 3.2.1.49) is a lysosomal exoglycosidase that cleaves terminal ?-N-acetylgalactosamine residues from glycopeptides and glycolipids. In humans, a deficiency of ?-NAGAL activity results in the lysosomal storage disorders Schindler disease and Kanzaki disease. To better understand the molecular defects in the diseases, we determined the crystal structure of human ?-NAGAL after expressing wild-type and glycosylation-deficient glycoproteins in recombinant insect cell expression systems. We measured the enzymatic parameters of our purified wild-type and mutant enzymes, establishing their enzymatic equivalence. To investigate the binding specificity and catalytic mechanism of the human ?-NAGAL enzyme, we determined three crystallographic complexes with different catalytic products bound in the active site of the enzyme. To better understand how individual defects in the ?-NAGAL glycoprotein lead to Schindler disease, we analyzed the effect of disease-causing mutations on the three-dimensional structure.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 980618
- Report Number(s):
- BNL-93536-2010-JA; JMOBAK; TRN: US201015%%2003
- Journal Information:
- Journal of Molecular Biology, Vol. 393, Issue 2; ISSN 0022-2836
- Country of Publication:
- United States
- Language:
- English
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