FEATURES

FAMILY

DESCRIPTION

Also known as HEXA_HUMAN, HEXA. Hydrolyzes the non-reducing end N-acetyl-D-hexosamine and/or sulfated N-acetyl-D-hexosamine of glycoconjugates, such as the oligosaccharide moieties from proteins and neutral glycolipids, or from certain mucopolysaccharides (PubMed:11707436, PubMed:9694901, PubMed:8672428, PubMed:8123671). The isozyme S is as active as the isozyme A on the anionic bis-sulfated glycans, the chondroitin-6-sulfate trisaccharide (C6S-3), and the dermatan sulfate pentasaccharide, and the sulfated glycosphingolipid SM2 (PubMed:11707436). The isozyme B does not hydrolyze each of these substrates, however hydrolyzes efficiently neutral oligosaccharide (PubMed:11707436). Only the isozyme A is responsible for the degradation of GM2 gangliosides in the presence of GM2A (PubMed:9694901, PubMed:8672428, PubMed:8123671). There are 3 beta-hexosaminidase isozymes: isozyme A (hexosaminidase A) is an heterodimer composed of one subunit alpha and one subunit beta (chain A and B); isozyme B (hexosaminidase B) is an homodimer of two beta subunits (two chains A and B); isozyme S (hexosaminidase S) is a homodimer of two alpha subunits (PubMed:16698036). The composition of the dimer (isozyme A versus isozyme S) has a significant effect on the substrate specificity of the alpha subunit active site (PubMed:8672428).

EXTERNAL LINKS

HEXA

Beta-hexosaminidase subunit alpha

HEXA

Molecular Synopsis