Α-Galactosidase

This article is about the enzyme. For the carbohydrate commonly called "alpha gal", see Galactose-alpha-1,3-galactose.

α-galactosidase
α-Galactosidase tetramer, Mortierella vinacea
Identifiers
EC no.3.2.1.22
CAS no.9025-35-8
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
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PMCarticles
PubMedarticles
NCBIproteins

α-Galactosidase ( EC 3.2.1.22, α-GAL, α-GAL A; systematic name α-D-galactoside galactohydrolase) is a glycoside hydrolase enzyme that catalyses the following reaction:[1]

Hydrolysis of terminal, non-reducing α-D-galactose residues in α-D-galactosides, including galactose oligosaccharides, galactomannans and galactolipids

It catalyzes many catabolic processes, including cleavage of glycoproteins, glycolipids, and polysaccharides.

The enzyme is encoded by the GLA gene.[2]

Function

This enzyme is a homodimeric glycoprotein that hydrolyses the terminal α-galactosyl moieties from glycolipids and glycoproteins. It predominantly hydrolyzes ceramide trihexoside, and it can catalyze the hydrolysis of melibiose into galactose and glucose.[citation needed]

Reaction mechanism

A double displacement reaction mechanism of α-GAL's catalytic action.The ligand (black) when bound in the active site of the enzyme (blue). The two key amino acid residues in the active site are Asp-170 and Asp-231. First, Asp-170 performs a nucleophilic attack on the glycosidic bond to release the terminal α-galactose molecule from the ligand. Then, Asp-231 serves as an acid to remove a proton from water, making it more nucleophilic to attack the galactose-Asp complex and release α-galactose from the active site.[3][4][5]

Applications

α-Galactosidase from Aspergillus niger is the active ingredient in Beano, a dietary supplement for bloating and flatulence.[6][7]

Recombinant α-Galactosidase made by baker's yeast is approved in Europe as a feed additive intended to make poultry food more digestible.[8]

See also

References

  1. ^ Scriver CR, Sly WS, Childs B, ABeaudet AL, Valle D, Kinzler KW, et al. (15 December 2000). The Metabolic & Molecular Basis of Inherited Disease (8th ed.). McGraw-Hill. ISBN 978-0-07-913035-8.
  2. ^ Calhoun DH, Bishop DF, Bernstein HS, Quinn M, Hantzopoulos P, Desnick RJ (November 1985). "Fabry disease: isolation of a cDNA clone encoding human α-galactosidase A". Proceedings of the National Academy of Sciences of the United States of America. 82 (21): 7364–8. Bibcode:1985PNAS...82.7364C. doi:10.1073/pnas.82.21.7364. PMC 391345. PMID 2997789.
  3. ^ Koshland DE (1953). "Stereochemistry and the Mechanism of Enzymatic Reactions". Biological Reviews. 28 (4): 416–436. doi:10.1111/j.1469-185x.1953.tb01386.x. S2CID 86709302.
  4. ^ Brumer H, Sims PF, Sinnott ML (April 1999). "Lignocellulose degradation by Phanerochaete chrysosporium: purification and characterization of the main α-galactosidase". The Biochemical Journal. 339 (1): 43–53. doi:10.1042/bj3390043. PMC 1220126. PMID 10085226.
  5. ^ Vocadlo DJ, Davies GJ (October 2008). "Mechanistic insights into glycosidase chemistry". Current Opinion in Chemical Biology. 12 (5): 539–55. doi:10.1016/j.cbpa.2008.05.010. PMID 18558099.
  6. ^ Di Stefano M, Miceli E, Gotti S, Missanelli A, Mazzoccahi S, Corazza GR (January 2007). "The effect of oral alpha-galactosidase on intestinal gas production and gas-related symptoms". Dig. Dis. Sci. 52 (1): 78–83. doi:10.1007/s10620-006-9296-9. PMID 17151807. S2CID 35435660.
  7. ^ Ganiats TG, Norcross WA, Halverson AL, Burford PA, Palinkas LA (November 1994). "Does Beano prevent gas? A double-blind crossover study of oral alpha-galactosidase to treat dietary oligosaccharide intolerance". J Fam Pract. 39 (5): 441–5. PMID 7964541.
  8. ^ Bampidis V, Azimonti G, Bastos ML, Christensen H, Dusemund B, Durjava M, et al. (August 2023). "Assessment of the feed additive consisting of alpha-galactosidase produced by Saccharomyces cerevisiaeCBS 615.94 and endo-1,4-beta-glucanase produced by Aspergillus nigerCBS 120604 (Agal-Pro BL/BL-L®) for use in chickens for fattening, minor poultry species for fattening and chickens reared for laying for the renewal of its authorisation (Kerry Ingredients & Flavours Ltd.)". EFSA Journal. European Food Safety Authority. 21 (8): e08175. doi:10.2903/j.efsa.2023.8175. PMC 10424062. PMID 37583944.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.