title: Characterization of sugar recognition by the toxin complex produced by the Clostridium botulinum serotype C variant strain Yoichi.
abstract: Clostridium botulinum serotype C strains produce a neurotoxin (BoNT) along with nontoxic proteins, including nontoxic nonhemagglutinin and three hemagglutinin subcomponents, HA-70, HA-33 and HA-17, to form a large toxin complex (L-TC). While L-TCs produced by serotype C strains usually exhibit hemagglutination (HA) activity via HA-33 binding to sialic acid on erythrocytes, serotype C strain Yoichi (C-Yoichi) L-TC exhibited neither HA nor binding activity towards erythrocytes, probably due to a C-terminal truncation of the HA-33 protein. However, here, we demonstrate that C-Yoichi L-TC newly showed full HA and binding activity towards neuraminidase-treated erythrocytes that was completely inhibited in the presence of galactose (Gal) or lactose (Lac). Binding of C-Yoichi L-TC to rat small intestine epithelial cells (IEC-6) treated with neuraminidase was also significantly enhanced compared with untreated IEC-6 cells. Similarly, the HA-33/HA-17 complex isolated from C-Yoichi L-TC also bound to neuraminidase-treated IEC-6 cells. The binding activity of both L-TC and HA-33/HA-17 was inhibited in the presence of Gal or Lac. Additionally, C-Yoichi L-TC adsorbed tightly to a lactose-affinity gel column. These results strongly suggest that the unusual recognition of the Gal moiety on the cells could be due to a variation and/or a truncation in the C-terminal-half of the unique C-Yoichi HA-33 protein.
authors.affiliation: Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Japan.
authors.forename: Tomohito
authors.initials: T
authors.lastname: Matsuo
authors.forename: Keita
authors.initials: K
authors.lastname: Miyata
authors.forename: Ken
authors.initials: K
authors.lastname: Inui
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ito
authors.forename: Ryohta
authors.initials: R
authors.lastname: Horiuchi
authors.forename: Tomonori
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tohru
authors.initials: T
authors.lastname: Yoneyama
authors.forename: Keiji
authors.initials: K
authors.lastname: Oguma
authors.forename: Koichi
authors.initials: K
authors.lastname: Niwa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
authors.forename: Tohru
authors.initials: T
authors.lastname: Ohyama
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D001905:Botulinum Toxins / Q000378:metabolism*; D003014:Clostridium botulinum / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D006388:Hemagglutinins / Q000378:metabolism; D011485:Protein Binding; D051381:Rats
chemical_list: D001426:Bacterial Proteins; D006388:Hemagglutinins; D001905:Botulinum Toxins; C096324:botulinum toxin type C; D005690:Galactose