Both hexosaminidase A and B can cleave GalNAc from globoside

Stable Identifier
Reaction [transition]
Homo sapiens
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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).

Literature References
PubMed ID Title Journal Year
2965147 Proteolytic processing of pro-alpha and pro-beta precursors from human beta-hexosaminidase. Generation of the mature alpha and beta a beta b subunits

Mahuran, DJ, Klavins, MH, Gravel, RA, Leung, A, Neote, K

J Biol Chem 1988
12662933 Crystal structure of human beta-hexosaminidase B: understanding the molecular basis of Sandhoff and Tay-Sachs disease

Knapp, S, Zhao, D, Mahuran, DJ, James, MN, Mark, BL, Cherney, MM

J Mol Biol 2003
2971395 Oligosaccharide structure and amino acid sequence of the major glycopeptides of mature human beta-hexosaminidase

Mahuran, D, Gravel, RA, Cumming, DA, O'Dowd, BF

Biochemistry 1988
Catalyst Activity

beta-N-acetylhexosaminidase activity of HEXA,B [lysosomal lumen]

Orthologous Events
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