title: Unique gangliosides synthesized in vitro by sialyltransferases from marine bacteria and their characterization: ganglioside synthesis by bacterial sialyltransferases.
abstract: On the basis of the results outlined in our previous report, bacterial sialyltransferases (ST) from marine sources were further characterized using glycosphingolipids (GSL), especially ganglio-series GSLs, based on the enzymatic characteristics and kinetic parameters obtained by Line weaver-Burk plots. Among them, GA1 and GA2 were found to be good substrates for these unique STs. Thus, new gangliosides synthesized by α2-3 and α2-6STs were structurally characterized by several analytical procedures. The ganglioside generated by the catalytic activity of α2-3ST was identified as GM1b. On the other hand, when enzyme reactions by α2-6STs were performed using substrates GA2 and GA1, very unique gangliosides were generated. The structures were identified as NeuAcα2-6GalNAcβ1-4Galβ1-4Glcβ-Cer and NeuAcα2-6Galβ1-3GalNAcβ1-4Galβ1-4Glcβ-Cer, respectively. The synthesized ganglioside NeuAcα2-6GalNAcβ1-4Galβ1-4Glcβ-Cer showed binding activity to the influenza A virus {A/Panama/2007/99 (H3N2)} at a similar level to purified sialyl(α2-3)paragloboside (S2-3PG) and sialyl(α2-6)paragloboside (S2-6PG) from mammalian sources. The evidence suggests that these STs have unique features, including substrate specificities restricted not only to lacto-series but also to ganglio-series GSLs, as well as catalytic potentials for ganglioside synthesis. This evidence demonstrates that effective in vitro ganglioside synthesis could be a valuable tool for selectively synthesizing sialic acid (Sia) modifications, thereby preparing large-scale gangliosides and permitting the exploration of unknown functions.
authors.affiliation: Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kamimiya
authors.affiliation: Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Instrumental Analysis Research Center, Tokyo Medical Dental University, Bunkyo-ku, Tokyo 113-8510, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kasama
authors.affiliation: Intellectual Property Center, Japan Tobacco Inc., Minato-ku, Tokyo 105-8422, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kajiwara
authors.affiliation: Product Science Division, Japan Tobacco Inc., Yokohama, Kanagawa 227-8512, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Plant Innovation Center, Japan Tobacco Inc., Iwata, Shizuoka 483-0802, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Mine
authors.affiliation: Laboratory of Veterinary Immunology, Division of Veterinary Science, Graduate School of Life and Environmental Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Watarai
authors.affiliation: Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ogura
authors.affiliation: Division of Biology, College of Liberal Arts and Sciences, Kitasato University School of Medicine, Sagamihara, Kanagawa 228-8555, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Junior College of Sapporo Otani University, Sapporo, Hokkaido 065-8567, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Tsuge
authors.affiliation: Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kushi
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D005732:Gangliosides / Q000737:chemistry*; D009980:Influenza A virus / Q000378:metabolism; D008386:Marine Biology; D013058:Mass Spectrometry; D012799:Sialyltransferases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005732:Gangliosides; D012799:Sialyltransferases