title: EndoE from Enterococcus faecalis hydrolyzes the glycans of the biofilm inhibiting protein lactoferrin and mediates growth.
abstract: Glycosidases are widespread among bacteria. The opportunistic human pathogen Enterococcus faecalis encodes several putative glycosidases but little is known about their functions. The identified endo-β-N-acetylglucosaminidase EndoE has activity on the N-linked glycans of the human immunoglobulin G (IgG). In this report we identified the human glycoprotein lactoferrin (hLF) as a new substrate for EndoE. Hydrolysis of the N-glycans from hLF was investigated using lectin blot, UHPLC and mass spectrometry, showing that EndoE releases major glycoforms from this protein. hLF was shown to inhibit biofilm formation of E. faecalis in vitro. Glycans of hLF influence the binding to E. faecalis, and EndoE-hydrolyzed hLF inhibits biofilm formation to lesser extent than intact hLF indicating that EndoE prevents the inhibition of biofilm. In addition, hLF binds to a surface-associated enolase of E. faecalis. Culture experiments showed that the activity of EndoE enables E. faecalis to use the glycans derived from lactoferrin as a carbon source indicating that they could be used as nutrients in vivo when no other preferred carbon source is available. This report adds important information about the enzymatic activity of EndoE from the commensal and opportunist E. faecalis. The activity on the human glycoprotein hLF, and the functional consequences with reduced inhibition of biofilm formation highlights both innate immunity functions of hLF and a bacterial mechanism to evade this innate immunity function. Taken together, our results underline the importance of glycans in the interplay between bacteria and the human host, with possible implications for both commensalism and opportunism.
authors.affiliation: Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden.
authors.forename: Julia
authors.initials: J
authors.lastname: Garbe
authors.affiliation: Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sjögren
authors.affiliation: Dublin Oxford Glycobiology Group, National Institute for Bioprocessing Research & Training (NIBRT), Mount Merrion, Blackrock, Co. Dublin, Ireland.
authors.forename: Eoin F J
authors.initials: EF
authors.lastname: Cosgrave
authors.affiliation: Dublin Oxford Glycobiology Group, National Institute for Bioprocessing Research & Training (NIBRT), Mount Merrion, Blackrock, Co. Dublin, Ireland.
authors.forename: Weston B
authors.initials: WB
authors.lastname: Struwe
authors.affiliation: Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden.
authors.forename: Marta
authors.initials: M
authors.lastname: Bober
authors.affiliation: Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden.
authors.forename: Anders I
authors.initials: AI
authors.lastname: Olin
authors.affiliation: Dublin Oxford Glycobiology Group, National Institute for Bioprocessing Research & Training (NIBRT), Mount Merrion, Blackrock, Co. Dublin, Ireland.
authors.forename: Pauline M
authors.initials: PM
authors.lastname: Rudd
authors.affiliation: Department of Clinical Sciences, Division of Infection Medicine, Lund University, Lund, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: Collin
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002240:Carbohydrate Sequence; D013293:Enterococcus faecalis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007781:Lactoferrin / Q000737:chemistry* / Q000494:pharmacology; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011134:Polysaccharides; D011994:Recombinant Proteins; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D007781:Lactoferrin; D010751:Phosphopyruvate Hydratase