Beta-Galactosidase Microplate Assay Kit

This gene encodes a member of the glycosyl hydrolase 35 family of proteins. Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed to generate the mature lysosomal enzyme. This enzyme catalyzes the hydrolysis of a terminal beta-linked galactose residue from ganglioside substrates and other glycoconjugates. Mutations in this gene may result in GM1-gangliosidosis and Morquio B syndrome. [provided by RefSeq, Nov 2015]

GLB1: Cleaves beta-linked terminal galactosyl residues from gangliosides, glycoproteins, and glycosaminoglycans. Defects in GLB1 are the cause of GM1-gangliosidosis type 1 (GM1G1); also known as infantile GM1- gangliosidosis. GM1-gangliosidosis is an autosomal recessive lysosomal storage disease marked by the accumulation of GM1 gangliosides, glycoproteins and keratan sulfate primarily in neurons of the central nervous system. GM1G1 is characterized by onset within the first three months of life, central nervous system degeneration, coarse facial features, hepatosplenomegaly, skeletal dysmorphology reminiscent of Hurler syndrome, and rapidly progressive psychomotor deterioration. Urinary oligosaccharide levels are high. It leads to death usually between the first and second year of life. Defects in GLB1 are the cause of GM1-gangliosidosis type 2 (GM1G2); also known as late infantile/juvenile GM1- gangliosidosis. GM1G2 is characterized by onset between ages 1 and 5. The main symptom is locomotor ataxia, ultimately leading to a state of decerebration with epileptic seizures. Patients do not display the skeletal changes associated with the infantile form, but they nonetheless excrete elevated amounts of beta-linked galactose-terminal oligosaccharides. Inheritance is autosomal recessive. Defects in GLB1 are the cause of GM1-gangliosidosis type 3 (GM1G3); also known as adult or chronic GM1- gangliosidosis. GM1G3 is characterized by a variable phenotype. Patients show mild skeletal abnormalities, dysarthria, gait disturbance, dystonia and visual impairment. Visceromegaly is absent. Intellectual deficit can initially be mild or absent but progresses over time. Inheritance is autosomal recessive. Defects in GLB1 are the cause of mucopolysaccharidosis type 4B (MPS4B); also known as Morquio syndrome B. MPS4B is a form of mucopolysaccharidosis type 4, an autosomal recessive lysosomal storage disease characterized by intracellular accumulation of keratan sulfate and chondroitin-6-sulfate. Key clinical features include short stature, skeletal dysplasia, dental anomalies, and corneal clouding. Intelligence is normal and there is no direct central nervous system involvement, although the skeletal changes may result in neurologic complications. There is variable severity, but patients with the severe phenotype usually do not survive past the second or third decade of life. Belongs to the glycosyl hydrolase 35 family. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: Glycan Metabolism - glycosaminoglycan degradation; Glycan Metabolism - glycosphingolipid biosynthesis - ganglio series; EC 3.2.1.23; Glycan Metabolism - other glycan degradation; Hydrolase; Carbohydrate Metabolism - galactose; Lipid Metabolism - sphingolipid

Chromosomal Location of Human Ortholog: 3p21.33

Cellular Component: cytoplasm; Golgi apparatus; intracellular membrane-bound organelle; lysosomal lumen; perinuclear region of cytoplasm

Molecular Function: beta-galactosidase activity; galactoside binding; protein binding

Biological Process: carbohydrate metabolic process; cellular carbohydrate metabolic process; cellular protein metabolic process; dolichol-linked oligosaccharide biosynthetic process; galactose catabolic process; glycosaminoglycan catabolic process; glycosaminoglycan metabolic process; glycosphingolipid metabolic process; keratan sulfate catabolic process; keratan sulfate metabolic process; post-translational protein modification; protein amino acid N-linked glycosylation via asparagine; sphingolipid metabolic process

Disease: Gm1-gangliosidosis, Type I; Gm1-gangliosidosis, Type Ii; Gm1-gangliosidosis, Type Iii; Mucopolysaccharidosis Type Ivb