Lysosomal β-galactosidase (β-Gal (GLB1))

Lysosomal β-galactosidase is a lysosomal exoglycosidase encoded by the GLB1 gene, which catalyzes the hydrolysis of terminal β-linked galactose residues from a variety of substrates including GM1 ganglioside, glycoproteins, and glycosaminoglycans[6][7]. Its deficiency leads to the accumulation of substrate in lysosomes, resulting in lysosomal storage diseases such as GM1 gangliosidosis (characterized by neurodegeneration) and Morquio B syndrome (characterized by skeletal abnormalities)[6][7]. Structurally, human β-galactosidase is organized as a TIM barrel catalytic domain followed by additional β-domains and typically operates in multienzyme complexes within the lysosome[6][4]. Assays for β-galactosidase activity and detection of substrate accumulation in tissues are used for diagnostic and monitoring purposes in affected patients[7]. The enzyme and its pathway are under investigation for enzyme replacement, gene, and substrate reduction therapies in related diseases[7].

Other names

Beta-galactosidaseGLB1 (gene/protein symbol)Acid beta-galactosidaseLysosomal beta-galactosidaseBeta-D-galactosidase

Competitive inhibition (for 1-deoxygalactonojirimycin and related compounds); Substrate reduction therapy (for agents like miglustat, reducing substrate burden in lysosomal storage conditions)