3S5Y image
Entry Detail
PDB ID:
3S5Y
Title:
Pharmacological Chaperoning in Human alpha-Galactosidase
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2011-05-23
Release Date:
2012-01-04
Method Details:
Experimental Method:
Resolution:
2.11 Å
R-Value Free:
0.22
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Alpha-galactosidase A
Chain IDs:A, B
Chain Length:398
Number of Molecules:2
Biological Source:Homo sapiens
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
ASN A ASN GLYCOSYLATION SITE
Primary Citation
The molecular basis of pharmacological chaperoning in human alpha-galactosidase
Chem.Biol. 18 1521 1526 (2011)
PMID: 22195554 DOI: 10.1016/j.chembiol.2011.10.012

Abstact

Fabry disease patients show a deficiency in the activity of the lysosomal enzyme α-galactosidase (α-GAL or α-Gal A). One proposed treatment for Fabry disease is pharmacological chaperone therapy, where a small molecule stabilizes the α-GAL protein, leading to increased enzymatic activity. Using enzyme kinetics, tryptophan fluorescence, circular dichroism, and proteolysis assays, we show that the pharmacological chaperones 1-deoxygalactonojirimycin (DGJ) and galactose stabilize the human α-GAL glycoprotein. Crystal structures of complexes of α-GAL and chaperones explain the molecular basis for the higher potency of DGJ over galactose. Using site-directed mutagenesis, we show the higher potency of DGJ results from an ionic interaction with D170. We propose that protonation of D170 in acidic conditions leads to weaker binding of DGJ. The results establish a biochemical basis for pharmacological chaperone therapy applicable to other protein misfolding diseases.

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Primary Citation of related structures