Beta-galactosidase 1 (GLB1) (GLB1)

Beta-galactosidase 1 (GLB1) is a critical lysosomal enzyme responsible for the hydrolysis of terminal beta-galactose residues from substrates such as GM1 gangliosides, keratan sulfate, and glycoproteins. Encoded by the GLB1 gene, the enzyme primarily functions within the acidic environment of the lysosome, though a splice variant also functions as an elastin-binding protein at the cell surface. Genetic mutations in GLB1 result in two severe lysosomal storage disorders: GM1 gangliosidosis, a progressive neurodegenerative condition, and Morquio syndrome type B, a systemic bone and skeletal disorder. In addition to its role in inherited diseases, beta-galactosidase is the most widely used biomarker for cellular senescence, as its activity at a specific pH (6.0) increases during the aging process and in pre-cancerous cells. Current therapeutic research focuses on restoring enzymatic function through gene therapy, using pharmacological chaperones to stabilize misfolded protein variants, or developing enzyme replacement therapies to mitigate substrate accumulation. In a biotechnological context, it is also frequently utilized as a reporter gene (lacZ) in molecular biology for monitoring gene expression and protein-protein interactions.

Other names

Acid beta-galactosidaseGLB1Elastin-binding protein (EBP)LactaseLysosomal beta-galactosidaseELNR1

Pharmacological chaperone (enzyme stabilization), Enzyme replacement therapy (ERT), Gene replacement therapy (AAV-mediated), Substrate reduction therapy (SRT)