| Structural highlights
Function
[GALT2_HUMAN] Catalyzes the initial reaction in O-linked oligosaccharide biosynthesis, the transfer of an N-acetyl-D-galactosamine residue to a serine or threonine residue on the protein receptor. Has a broad spectrum of substrates for peptides such as EA2, Muc5AC, Muc1a, Muc1b. Probably involved in O-linked glycosylation of the immunoglobulin A1 (IgA1) hinge region.[1] [2]
Publication Abstract from PubMed
The Leloir donors are nucleotide sugars essential for a variety of glycosyltransferases (GTs) involved in the transfer of a carbohydrate to an acceptor substrate, typically a protein or an oligosaccharide. A series of less-polar nucleotide sugar analogues derived from uridine have been prepared by replacing one phosphate unit with an alkyl chain. The methodology is based on the radical hydrophosphonylation of alkenes, which allows coupling of allyl glycosyl compounds with a phosphate unit suitable for conjugation to uridine. Two of these compounds, the GalNAc and galactose derivatives, were further tested on a model GT, such as GalNAc-T2 (an important GT widely distributed in human tissues), to probe that both compounds bound in the medium-high micromolar range. The crystal structure of GalNAc-T2 with the galactose derivative traps the enzyme in an inactive form; this suggests that compounds only containing the beta-phosphate could be efficient ligands for the enzyme. Computational studies with GalNAc-T2 corroborate these findings and provide further insights into the mechanism of the catalytic cycle of this family of enzymes.
Glycomimetics Targeting Glycosyltransferases: Synthetic, Computational and Structural Studies of Less-Polar Conjugates.,Ghirardello M, de Las Rivas M, Lacetera A, Delso I, Lira-Navarrete E, Tejero T, Martin-Santamaria S, Hurtado-Guerrero R, Merino P Chemistry. 2016 May 17;22(21):7215-24. doi: 10.1002/chem.201600467. Epub 2016 Apr, 13. PMID:27071848[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wandall HH, Hassan H, Mirgorodskaya E, Kristensen AK, Roepstorff P, Bennett EP, Nielsen PA, Hollingsworth MA, Burchell J, Taylor-Papadimitriou J, Clausen H. Substrate specificities of three members of the human UDP-N-acetyl-alpha-D-galactosamine:Polypeptide N-acetylgalactosaminyltransferase family, GalNAc-T1, -T2, and -T3. J Biol Chem. 1997 Sep 19;272(38):23503-14. PMID:9295285
- ↑ Iwasaki H, Zhang Y, Tachibana K, Gotoh M, Kikuchi N, Kwon YD, Togayachi A, Kudo T, Kubota T, Narimatsu H. Initiation of O-glycan synthesis in IgA1 hinge region is determined by a single enzyme, UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 2. J Biol Chem. 2003 Feb 21;278(8):5613-21. Epub 2002 Nov 15. PMID:12438318 doi:http://dx.doi.org/10.1074/jbc.M211097200
- ↑ Ghirardello M, de Las Rivas M, Lacetera A, Delso I, Lira-Navarrete E, Tejero T, Martin-Santamaria S, Hurtado-Guerrero R, Merino P. Glycomimetics Targeting Glycosyltransferases: Synthetic, Computational and Structural Studies of Less-Polar Conjugates. Chemistry. 2016 May 17;22(21):7215-24. doi: 10.1002/chem.201600467. Epub 2016 Apr, 13. PMID:27071848 doi:http://dx.doi.org/10.1002/chem.201600467
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