title: Serum GlcNAc-binding IgM of fugu (Takifugu rubripes) suppresses the growth of fish pathogenic bacteria: a novel function of teleost antibody.
abstract: N-acetyl-d-glucosamine (GlcNAc) is one of the components of peptidoglycan, a biopolymer in the bacterial cell wall. We purified a novel GlcNAc-binding protein, designated as fGBP-78, from sera of fugu (Takifugu rubripes). The fGBP-78 is a heteromer of 78- and 25-kDa subunits. Moreover, fGBP-78 exerted remarkable inhibitory effects on the growth of both Gram-positive and Gram-negative bacteria, including ones virulent for marine fish species as well as non-pathogenic Escherichia coli. These results suggest that fGBP-78 contributes to bacterial clearance in fugu. Furthermore, the nanoLC-MS/MS and Western blotting analyses reveal that the 78-kDa subunit is the fugu IgM heavy chain. In addition, the molecular mass of the other subunit (25 kDa) was equal to that of the Ig light chain. Overall, results indicate that fGBP-78 is an IgM molecule presumably acts as a natural antibody. This paper reports a novel function of teleost IgM as a significant suppresser against bacterial growth.
authors.affiliation: School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 252-0373, Japan. tsutsui@kitasato-u.ac.jp
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tsutsui
authors.forename: Toru
authors.initials: T
authors.lastname: Ariji
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.forename: Takaya
authors.initials: T
authors.lastname: Yoshida
authors.forename: Nozomi
authors.initials: N
authors.lastname: Yamamura
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Odaka
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Araki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suetake
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyadai
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakamura
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D002352:Carrier Proteins / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D029941:Fish Proteins / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D007113:Immunity, Innate; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D008969:Molecular Sequence Data; D011485:Protein Binding; D055503:Protein Multimerization; D021122:Protein Subunits / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D023741:Takifugu / Q000097:blood / Q000235:genetics / Q000276:immunology* / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D002352:Carrier Proteins; D029941:Fish Proteins; D007075:Immunoglobulin M; D021122:Protein Subunits; D000117:Acetylglucosamine