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. The isozyme B does not hydrolyze each of these substrates, however hydrolyzes efficiently neutral oligosaccharide. Only the isozyme A is responsible for the degradation of GM2 gangliosides in the presence of GM2A (By similarity). During fertilization is responsible, at least in part, for the zona block to polyspermy. Present in the cortical granules of non-activated oocytes, is exocytosed during the cortical reaction in response to oocyte activation and inactivates the sperm galactosyltransferase-binding site, accounting for the block in sperm binding to the zona pellucida (By similarity). Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. H2O + N-acetyl-beta-D-galactosaminyl-(1->4)-beta-D-3-sulfogalactosyl-(1->4)-beta-D-glucosyl-(1<->1')-ceramide = a beta-D-3-sulfogalactosyl-(1->4)-beta-D-glucosyl-(1<->1')-ceramide + N-acetyl-beta-D-galactosamine ganglioside GM2 (d18:1(4E)) + H2O = ganglioside GM3 (d18:1(4E)) + N-acetyl-beta-D-galactosamine ganglioside GM2 + H2O = ganglioside GM3 + N-acetyl-beta-D-galactosamine beta-D-GalNAc-(1->4)-alpha-L-IdoA-(1->3)-beta-D-GalNAc-4-sulfate-(1->4)-alpha-L-IdoA-(1->3)-D-GalNAc-4-sulfate + H2O = alpha-L-IdoA-(1->3)-beta-D-GalNAc-4-sulfate-(1->4)-alpha-L-IdoA-(1->3)-D-GalNAc-4-sulfate + N-acetyl-D-galactosamine H2O + N-acetyl-beta-D-6-sulfogalactosaminyl-(1->4)-alpha-L-iduronyl-(1->3)-N-acetyl-D-6-sulfogalactosamine = alpha-L-iduronyl-(1->3)-N-acetyl-D-6-sulfogalactosamine + N-acetyl-D-6-sulfogalactosamine Addition of GM2A stimulates the hydrolysis of sulfated glycosphingolipid SM2 and the ganglioside GM2. There are 3 forms of beta-hexosaminidase: hexosaminidase A is an heterodimer composed of one subunit alpha and one subunit beta (chain A and B); hexosaminidase B is an homodimer of two beta subunits (two chains A and B); hexosaminidase S is a homodimer of two alpha subunits (By similarity). The composition of the dimer (isozyme A versus isozyme S) has a significant effect on the substrate specificity of the alpha subunit active site (By similarity). Belongs to the glycosyl hydrolase 20 family.