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Bifidobacterial Endoglycosidases Release Complex N‐linked Glycans from Host Glycoproteins
Author(s) -
GARRIDO DANIEL,
Nwosu Charles,
Ruiz-Moyano Santiago,
Aldredge Danielle,
German J. Bruce,
Lebrilla Carlito B.,
Mills David A
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.lb358
Subject(s) - fucosylation , glycoprotein , endoglycosidase , glycan , glycosylation , biochemistry , biology , mucin , fucose , microbiology and biotechnology , chemistry
Breastfeeding is one of the main factors guiding the composition of the gut microbiota in the infant. This process is shaped by the high amounts of human milk oligosaccharides that serve as a carbon source for gut bacteria such as Bifidobacterium species. We hypothesized that they also interact with structurally similar N‐glycans found on glycoproteins present in human milk and the intestinal epithelium. Genes encoding endo‐B‐N‐acetylglucosaminidases were identified in certain isolates of bifidobacteria, and their presence correlated with their ability to deglycosylate glycoproteins. An endoglycosidase from B. infantis ATCC 15697, EndoBI‐1, was active towards all major types of N‐linked glycans. EndoBI‐1 activity was not affected by core fucosylation or extensive fucosylation, antenna number or sialylation, releasing several N‐glycans from human lactoferrin and immunoglobulins A and G. Extensive N‐deglycosylation of whole breast milk was also observed after coincubation with EndoBI‐1. Mutation of the active site of EndoBI‐1 did not abolish binding to N‐glycosylated proteins, and this mutant specifically recognized Man3GlcNAc2Fuc, the core structure of human N‐glycans. This work reveals an unprecedented interaction of bifidobacteria with host N‐glycans, and describes the properties of EndoBI‐1, a novel endoglycosidase active on diverse host glycoproteins with varying N‐glycosylation types