title: Identification of OmpA-Like Protein of Tannerella forsythia as an O-Linked Glycoprotein and Its Binding Capability to Lectins.
abstract: Bacterial glycoproteins are associated with physiological and pathogenic functions of bacteria. It remains unclear whether bacterial glycoproteins can bind to specific classes of lectins expressed on host cells. Tannerella forsythia is a gram-negative oral anaerobe that contributes to the development of periodontitis. In this study, we aimed to find lectin-binding glycoproteins in T. forsythia. We performed affinity chromatography of wheat germ agglutinin, which binds to N-acetylglucosamine (GlcNAc) and sialic acid (Sia), and identified OmpA-like protein as the glycoprotein that has the highest affinity. Mass spectrometry revealed that OmpA-like protein contains O-type N-acetylhexosamine and hexose. Fluorometry quantitatively showed that OmpA-like protein contains Sia. OmpA-like protein was found to bind to lectins including E-selectin, P-selectin, L-selectin, Siglec-5, Siglec-9, Siglec-10, and DC-SIGN. The binding of OmpA-like protein to these lectins, except for the Siglecs, depends on the presence of calcium. N-acetylneuraminic acid (NeuAc), which is the most abundant Sia, inhibited the binding of OmpA-like protein to all of these lectins, whereas GlcNAc and mannose only inhibited the binding to DC-SIGN. We further found that T. forsythia adhered to human oral epithelial cells, which express E-selectin and P-selectin, and that this adhesion was inhibited by addition of NeuAc. Moreover, adhesion of an OmpA-like protein-deficient T. forsythia strain to the cells was reduced compared to that of the wild-type strain. Our findings indicate that OmpA-like protein of T. forsythia contains O-linked sugar chains that can mediate interactions with specific lectins. This interaction is suggested to facilitate adhesion of T. forsythia to the surface of host cells.
authors.affiliation: Department of Oral Microbiology, Division of Oral Infections and Health Sciences, Asahi University School of Dentistry, Mizuho, Gifu, Japan.|Department of Orthodontics, Division of Oral Structure, Function and Development, Asahi University School of Dentistry, Mizuho, Gifu, Japan.
authors.forename: Toshi
authors.initials: T
authors.lastname: Horie
authors.affiliation: Department of Oral Microbiology, Division of Oral Infections and Health Sciences, Asahi University School of Dentistry, Mizuho, Gifu, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Inomata
authors.affiliation: Department of Oral Microbiology, Division of Oral Infections and Health Sciences, Asahi University School of Dentistry, Mizuho, Gifu, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Into
authors.affiliation: Department of Microbiology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hasegawa
authors.affiliation: Department of Orthodontics, Division of Oral Structure, Function and Development, Asahi University School of Dentistry, Mizuho, Gifu, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kitai
authors.affiliation: Department of Microbiology, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi, Japan.
authors.forename: Fuminobu
authors.initials: F
authors.lastname: Yoshimura
authors.affiliation: Department of Oral Microbiology, Division of Oral Infections and Health Sciences, Asahi University School of Dentistry, Mizuho, Gifu, Japan.
authors.forename: Yukitaka
authors.initials: Y
authors.lastname: Murakami
mesh_terms: D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry*; D011485:Protein Binding; D000070436:Tannerella forsythia / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D006023:Glycoproteins; D037102:Lectins; C078167:OMPA outer membrane proteins; D010100:Oxygen