The GLB1 gene encodes beta-galactosidase-1 (EC 3.2.1.23)，a lysosomal hydrolase that cleaves the terminal beta-galactose from ganglioside substrates and other glycoconjugates (Yoshida et al.，1991 [PubMed 1907800]). Beta-galactosidase also occurs in a complex with neuraminidase (NEU1; MIM 608272) and protective protein/cathepsin A (PPCA; MIM 256540)，which is a component of certain cell surface receptors. This protein has no beta-galactosidase catalytic activity，but plays functional roles in the formation of extracellular elastic fibers (elastogenesis) and in the development of connective tissue. Seems to be identical to the elastin-binding protein (EBP)，a major component of the non- integrin cell surface receptor expressed on fibroblasts，smooth muscle cells，chondroblasts，leukocytes，and certain cancer cell types. In elastin producing cells，associates with tropoelastin intracellularly and functions as a recycling molecular chaperone which facilitates the secretions of tropoelastin and its assembly into elastic fibers. Cleaves beta-linked terminal galactosyl residues from gangliosides，glycoproteins，and glycosaminoglycans.
