Glycopeptide alpha-N-acetylgalactosaminidase explained

Endo-α-N-acetylgalactosaminidase
Ec Number:	3.2.1.97
Cas Number:	59793-96-3

Endo-α-N-acetylgalactosaminidase (endo-α-acetylgalactosaminidase, endo-α-N-acetyl-D-galactosaminidase, mucinaminylserine mucinaminidase, D-galactosyl-3-(N-acetyl-α-D-galactosaminyl)-L-serine mucinaminohydrolase, endo-α-GalNAc-ase, D-galactosyl-N-acetyl-α-D-galactosamine D-galactosyl-N-acetyl-galactosaminohydrolase) is an enzyme with systematic name glycopeptide-D-galactosyl-N-acetyl-α-D-galactosamine D-galactosyl-N-acetyl-galactosaminohydrolase.^{[1] [2] [3] [4] [5] [6] [7]} This enzyme catalyses the following chemical reaction

3-O-beta-D-galactosyl-N-acetyl-alpha-D-galactosaminyl-L-serine-[protein] + H₂O

\rightleftharpoons 3-O-beta-D-galactosyl-N-acetyl-alpha-D-galactosamine + L-serine-[protein]

The enzyme catalyses the release of Gal-(1->3)-beta-GalNAc alpha-linked to serine or threonine residues of mucin-type glycoproteins.

Glycopeptide α-N-acetylgalactosaminidases belong to family GH101 of glycoside hydrolases.^[8]

Notes and References

1. Ashida H, Maki R, Ozawa H, Tani Y, Kiyohara M, Fujita M, Imamura A, Ishida H, Kiso M, Yamamoto K . Characterization of two different endo-alpha-N-acetylgalactosaminidases from probiotic and pathogenic enterobacteria, Bifidobacterium longum and Clostridium perfringens . Glycobiology . 18 . 9 . 727–34 . September 2008 . 18559962 . 10.1093/glycob/cwn053 . free .
2. Koutsioulis D, Landry D, Guthrie EP . Novel endo-alpha-N-acetylgalactosaminidases with broader substrate specificity . Glycobiology . 18 . 10 . 799–805 . October 2008 . 18635885 . 2553423 . 10.1093/glycob/cwn069 .
3. Fujita K, Oura F, Nagamine N, Katayama T, Hiratake J, Sakata K, Kumagai H, Yamamoto K . Identification and molecular cloning of a novel glycoside hydrolase family of core 1 type O-glycan-specific endo-alpha-N-acetylgalactosaminidase from Bifidobacterium longum . The Journal of Biological Chemistry . 280 . 45 . 37415–22 . November 2005 . 16141207 . 10.1074/jbc.m506874200 . free .
4. Suzuki R, Katayama T, Kitaoka M, Kumagai H, Wakagi T, Shoun H, Ashida H, Yamamoto K, Fushinobu S . Crystallographic and mutational analyses of substrate recognition of endo-alpha-N-acetylgalactosaminidase from Bifidobacterium longum . Journal of Biochemistry . 146 . 3 . 389–98 . September 2009 . 19502354 . 10.1093/jb/mvp086 .
5. Gregg KJ, Boraston AB . Cloning, recombinant production, crystallization and preliminary X-ray diffraction analysis of a family 101 glycoside hydrolase from Streptococcus pneumoniae . Acta Crystallographica Section F . 65 . Pt 2 . 133–5 . February 2009 . 19194003 . 2635869 . 10.1107/s1744309108042474 .
6. Ashida H, Yamamoto K, Murata T, Usui T, Kumagai H . Characterization of endo-alpha-N-acetylgalactosaminidase from Bacillus sp. and syntheses of neo-oligosaccharides using its transglycosylation activity . Archives of Biochemistry and Biophysics . 373 . 2 . 394–400 . January 2000 . 10620364 . 10.1006/abbi.1999.1565 .
7. Goda HM, Ushigusa K, Ito H, Okino N, Narimatsu H, Ito M . Molecular cloning, expression, and characterization of a novel endo-alpha-N-acetylgalactosaminidase from Enterococcus faecalis . Biochemical and Biophysical Research Communications . 375 . 4 . 441–6 . October 2008 . 18725192 . 10.1016/j.bbrc.2008.08.065 .
8. Naumoff DG . GH101 family of glycoside hydrolases: subfamily structure and evolutionary connections with other families . Journal of Bioinformatics and Computational Biology . 8 . 3 . 437–51 . June 2010 . 20556855 . 10.1142/s0219720010004628 .