Syntheses of mucin-type O-glycopeptides and oligosaccharides using transglycosylation and reverse-hydrolysis activities of Bifidobacterium endo-alpha-N-acetylgalactosaminidase.
Endo-alpha-N-acetylgalactosaminidase catalyzes the release of Galbeta1-3GalNAc from the core 1-type O-glycan (Galbeta1-3GalNAcalpha1-Ser/Thr) of mucin glycoproteins and synthetic p-nitrophenyl (pNP) alpha-linked substrates. Here, we report the enzymatic syntheses of core 1 disaccharide-containing glycopeptides using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase (EngBF) from Bifidobacterium longum. The enzyme directly transferred Galbeta1-3GalNAc to serine or threonine residues of bioactive peptides such as PAMP-12, bradykinin, peptide-T and MUC1a when Galbeta1-3GalNAcalpha1-pNP was used as a donor substrate. The enzyme was also found to catalyze the reverse-hydrolysis reaction. EngBF synthesized the core 1 disaccharide-containing oligosaccharides when the enzyme was incubated with either glucose or lactose and Galbeta1-3GalNAc prepared from porcine gastric mucin using bifidobacterial cells expressing endo-alpha-N-acetylgalactosaminidase. Synthesized oligosaccharides are promising prebiotics for bifidobacteria.
Ashida
Hisashi
H
Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan. ashida@lif.kyoto-u.ac.jp
Ozawa
Hayato
H
Fujita
Kiyotaka
K
Suzuki
Shun'ichi
S
Yamamoto
Kenji
K
D000595:Amino Acid Sequence; D000818:Animals; D001644:Bifidobacterium / Q000166:cytology / Q000201:enzymology*; D005688:Galactosamine / Q000378:metabolism; D005752:Gastric Mucins / Q000096:biosynthesis*; D006020:Glycopeptides / Q000096:biosynthesis* / Q000737:chemistry; D006031:Glycosylation; D006868:Hydrolysis; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000096:biosynthesis*; D012694:Serine / Q000378:metabolism; D034421:Sus scrofa; D013912:Threonine / Q000378:metabolism; D048809:alpha-N-Acetylgalactosaminidase / Q000378:metabolism*
D005752:Gastric Mucins; D006020:Glycopeptides; D009844:Oligosaccharides; D013912:Threonine; D012694:Serine; D005688:Galactosamine; D048809:alpha-N-Acetylgalactosaminidase