The 1.9 Astroms Structure of Human α-N-Acetylgalactosaminidase: The Molecular Basis of Schindler and Kanzaki Diseases

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Journal of Molecular Biology

DOI:https://doi.org/10.1016/j.jmb.2009.08.021· OSTI ID:980618

Clark, N; Garman, S

?-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 Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 980618
• Report Number(s): BNL--93536-2010-JA
• Journal Information: Journal of Molecular Biology, Journal Name: Journal of Molecular Biology Journal Issue: 2 Vol. 393; ISSN JMOBAK; ISSN 0022-2836
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPLEXES
CRYSTAL STRUCTURE
DEFECTS
DISEASES
ENZYMES
GLYCOLIPIDS
GLYCOPROTEINS
HUMAN POPULATIONS
INSECTS
MUTANTS
MUTATIONS
RESIDUES
SPECIFICITY
STORAGE
national synchrotron light source