GLB1

Galactosidase, beta 1, also known as GLB1, is a protein which in humans is encoded by the GLB1 gene.

The GLB1 protein is a beta-galactosidase that cleaves the terminal beta-galactose from ganglioside substrates and other glycoconjugates. The GLB1 gene also encodes an elastin binding protein.

In corn (Zea mays), Glb1 is a gene coding for the storage protein globulin.

Clinical significance

GM1-gangliosidosis is a lysosomal storage disease that can be caused by a deficiency of β-galactosidase (GLB1). Some cases of Morquio syndrome B have been shown to be due to GLP1 mutations that cause patients to have abnormal elastic fibers.

Elastin receptor

The RNA transcript of the GLB1 gene is alternatively spliced and produces 2 mRNAs. The 2.5-kilobase transcript encodes the beta-galactosidase enzyme of 677 amino acids. The alternative 2.0-kb mRNA encodes a beta-galactosidase-related protein (S-Gal) that is only 546 amino acids long and that has no enzymatic activity. The S-Gal protein does bind elastin and fragments of elastin that are generated by proteolysis.