Galactosylceramidase (or galactocerebrosidase) is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
that in humans is encoded by the ''GALC''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Galactosylceramidase is an enzyme which removes
galactose
Galactose (, '' galacto-'' + ''-ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecu ...
from
ceramide
Ceramides are a family of waxy lipid molecules. A ceramide is composed of N-acetyl sphingosine and a fatty acid. Ceramides are found in high concentrations within the cell membrane of eukaryotic cells, since they are component lipids that make ...
derivatives (
galactosylceramide
A galactosylceramide, or galactocerebroside is a type of cerebroside consisting of a ceramide with a galactose residue at the 1-hydroxyl moiety.
The galactose is cleaved by galactosylceramidase.
Galactosylceramide is a marker for oligodendrocyt ...
s).
Galactosylceramidase is a
lysosomal
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane pro ...
protein which hydrolyzes the
galactose
Galactose (, '' galacto-'' + ''-ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecu ...
ester bonds of
galactosylceramide
A galactosylceramide, or galactocerebroside is a type of cerebroside consisting of a ceramide with a galactose residue at the 1-hydroxyl moiety.
The galactose is cleaved by galactosylceramidase.
Galactosylceramide is a marker for oligodendrocyt ...
, galactosylsphingosine,
lactosylceramide
The Lactosylceramides, also known as LacCer, are a class of glycosphingolipids composed of a variable hydrophobic ceramide lipid and a hydrophilic sugar moiety. Lactosylceramides are found in microdomains on the plasma layers of numerous cells. ...
, and monogalactosyldiglyceride.
Mutations in this gene have been associated with
Krabbe disease
Krabbe disease (KD) (also known as globoid cell leukodystrophy or galactosylceramide lipidosis) is a rare and often fatal lysosomal storage disease that results in progressive damage to the nervous system. KD involves dysfunctional metabolism of ...
, also known as galactosylceramide lipidosis.
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Krabbe disease OMIM entries on Krabbe disease*
PDBe-KBprovides an overview of all the structure information available in the PDB for Mlouse Galactocerebrosidase
EC 3.2.1
{{3.2-enzyme-stub