title: Lactobacillus rhamnosus GG SpaC pilin subunit binds to the carbohydrate moieties of intestinal glycoconjugates.
abstract: Lactobacillus rhamnosus GG (LGG) is a well-established probiotic strain. The beneficial properties of this strain are partially dependent on its prolonged residence in the gastrointestinal tract, and are likely influenced by its adhesion to the intestinal mucosa. The pilin SpaC subunit, located within the Spa pili structure, is the most well studied LGG adhesion factor. However, the binding epitopes of SpaC remain largely unknown. The aim of this study was to evaluate the binding properties of SpaC to the carbohydrate moieties of intestinal glycoconjugates using a recombinant SpaC protein. In a competitive enzyme-linked immunosorbent assay, SpaC binding was markedly reduced by addition of purified mucin and the mucin oligosaccharide fraction. Histochemical staining revealed that the binding of SpaC was drastically reduced by periodic acid treatment. Moreover, in the surface plasmon resonance-based Biacore assay, SpaC bound strongly to the carbohydrate moieties containing β-galactoside at the non-reducing terminus of glycolipids. We here provide the first demonstration that SpaC binds to the oligosaccharide chains of mucins, and that the carbohydrate moieties containing β-galactoside at the non-reducing termini of glycoconjugates play a crucial role in this binding. Our results demonstrate the importance of carbohydrates of SpaC for mucus interactions.
authors.affiliation: Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada.|Department of Microbiology, School of Pharmacy, Kitasato University, Minato-ku, Tokyo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Nishiyama
authors.affiliation: Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Ueno
authors.affiliation: Faculty of Veterinary Medicine, School of Veterinary Medicine, Kitasato University, Towada, Aomori, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sugiyama
authors.affiliation: Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada.
authors.forename: Takao
authors.initials: T
authors.lastname: Mukai
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D036781:Fimbriae Proteins / Q000378:metabolism*; D005697:Galactosides / Q000378:metabolism; D006001:Glycoconjugates / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology; D052201:Lacticaseibacillus rhamnosus / Q000502:physiology; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D009077:Mucins / Q000737:chemistry; D009844:Oligosaccharides / Q000378:metabolism; D010504:Periodic Acid / Q000494:pharmacology; D019936:Probiotics; D011485:Protein Binding / Q000187:drug effects; D011994:Recombinant Proteins
chemical_list: D001426:Bacterial Proteins; D005697:Galactosides; D006001:Glycoconjugates; D008565:Membrane Proteins; D009077:Mucins; D009844:Oligosaccharides; D011994:Recombinant Proteins; C104625:SpaC protein, bacteria; D010504:Periodic Acid; D036781:Fimbriae Proteins
keywords: Lactobacillus rhamnosus GG; adhesion; glycoconjugate; pilus