Garman lab: Interconversion of lysosomal enzyme specificities: Difference between revisions

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== Lysosomal storage disease ==
== Lysosomal storage disease ==
Lysosomal storage disorders are inherited metabolic diseases characterized by an accumulation of undigested various toxic materials.  There are nearly 50 diseases and the two examples shown here are Fabry and Schindler disease.  Fabry disease, which occurs between early childhood and adolescence, is characterized by the lack of the enzyme alpha galactosidase (α-Gal).  Schindler disease can occur in infancy or in adulthood and is characterized by the lack on the enzyme alpha N-acetylgalactosaminidase (α-NaGal).  There are currently no cures for lysosomal storage disorders however enzyme replacement therapy is a treatment option.  The basic principle of enzyme replacement therapy is to over express the enzyme of interest heterologously, in this case α-Gal α-NaGal, in a cell line and to isolate and purify it from the culture.  In enzyme replacement therapy, patients are injected with the enzymes that they lack in the hopes of restoring the enzymatic activity in their cells.


== Immune Response ==
== Immune Response ==

Revision as of 20:43, 1 May 2018

About this pageAbout this page

Lysosomal storage diseaseLysosomal storage disease

Lysosomal storage disorders are inherited metabolic diseases characterized by an accumulation of undigested various toxic materials. There are nearly 50 diseases and the two examples shown here are Fabry and Schindler disease. Fabry disease, which occurs between early childhood and adolescence, is characterized by the lack of the enzyme alpha galactosidase (α-Gal). Schindler disease can occur in infancy or in adulthood and is characterized by the lack on the enzyme alpha N-acetylgalactosaminidase (α-NaGal). There are currently no cures for lysosomal storage disorders however enzyme replacement therapy is a treatment option. The basic principle of enzyme replacement therapy is to over express the enzyme of interest heterologously, in this case α-Gal α-NaGal, in a cell line and to isolate and purify it from the culture. In enzyme replacement therapy, patients are injected with the enzymes that they lack in the hopes of restoring the enzymatic activity in their cells.

Immune ResponseImmune Response

Individuals suffering from Fabry disease cannot produce the Alpha-Gal protein that is necessary for breaking down Galactose. The usual treatment for this is giving the patient doses of the protein, but this poses a problem. Since the body does not produce the protein, an immune response ranging from severe anaphylaxis to mild discomfort can occur when the patient is given the protein. The body does however produce Alpha NAGAL, a protein with a similar active site and function as Alpha Gal. Altering the active site of Alpha NAGAL to match that of Alpha Gal allows doctors to administer a protein that serves the function of Alpha Gal but has the antigenicity of Alpha NAGAL, which means the body will recognize the protein and not elicit an immune response.

Enzymatic activityEnzymatic activity

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Structures shown on this pageStructures shown on this page

3H54: alpha-NAGAL with GalNAc

3HG5: alpha-GAL with Gal

3LX9: alpha-GAL(SA) in complex with GalNAc

3LXA: alpha-GAL(SA) in complex with Galactose

3LXC: alpha-GAL(SA) in presence of Glycerol



Figure 1

Panel B ()

Panel C (show )



Figure 2: Structure of alpha-GAL(SA)

: in complex with GalNAc

Crystal structure of alpha-GAL(SA) bound to GalNAc. Alpha-GAL(SA) active site residues are shown in yellow and the product, GalNAc, is shown in gray. The blue frame around GalNAc represents its electron density. Red and blue dots in the figure represent oxygen and hydrogen, respectively.

: Superposition with alpha-NAGAL bound to GalNAc


Drag the structure with the mouse to rotate

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Karsten Theis