There are two major forms of bHEX: hexosaminidase A and B. The A form is a trimer of the subunits alpha, beta A and beta B. The B form is a tetramer of 2 beta A and 2 beta B subunits (O'Dowd et al. 1988, Mahuran et al. 1988). Both are able to cleave GalNAc from globoside (a glycosphingolipid with more than one sugar attached as the side chain). Here, globoside is cleaved to form Gb3Cer (a globotriaosylceramide) (Mark et al. 2003).