Globotriaosylceramide is a globoside.[1] It is also known as CD77, Gb3, GL3, and ceramide trihexoside.[2] It is one of the few clusters of differentiation that is not a protein.
It is formed by the alpha linkage of galactose to lactosylceramide catalyzed by A4GALT.
It is metabolized by alpha-galactosidase, which hydrolyzes the terminal alpha linkage.
Clinical significance
Defects in the enzyme alpha-galactosidase lead to the buildup of globotriaosylceramide, causing Fabry's disease.[3] The pharmaceutical drug migalastat enhances the function of alpha-galactosidase and is used to treat Fabry's.
Globotriaosylceramide is also one of the targets of Shiga toxin, which is responsible for pathogenicity of enterohemorrhagic Escherichia coli (EHEC).[citation needed]
The bacterial Shiga toxin can be used for targeted therapy of certain gastrointestinal cancers that express the receptor of the Shiga toxin.[4] For this purpose a non-specific chemotherapeutic agent is conjugated to the B-subunit to make it specific. In this way only the tumor cells, but not healthy cells, should be destroyed during therapy.[5]