title: A Novel Chemoenzymatic Synthesis of Sulfated Type 2 Tumor-Associated Carbohydrate Antigens by Transglycosylation of Sulfated Lewis X Oxazoline Catalyzed by Keratanase II.
abstract: Sulfated type 2 carbohydrate chains are known tumor-associated carbohydrate antigens (TACAs). Many reports on cancer vaccines employing TACAs as specific antigens have been published, but structurally specified sulfated TACAs have not been used because of the low natural abundance and difficulties in chemical synthesis. We demonstrate for the first time the synthesis of the sulfated type 2 TACAs with an l-fucose branch by keratanase-II-catalyzed transglycosylation of the sulfated Lewis X (Galβ(1→4)[Fucα(1→3)]GlcNAc(6-OSO3-); su-Lex) oxazoline derivative. Two keratanase IIs (from Bacillus sp. Ks36 and Bacillus circulans KsT202) efficiently catalyzed the transglycosylation reaction of the su-Lexoxazoline derivative, thereby giving the su-Lexdimer as the main product in good yields. Structural analysis of the oligomers confirmed exclusive formation of the β(1→3) glycosidic bond.
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku-katsura, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamazaki
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku-katsura, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Kyohei
authors.initials: K
authors.lastname: Sezukuri
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku-katsura, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Takada
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku-katsura, Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku-katsura, Nishikyo-ku, Kyoto, 615-8510, Japan. ohmae@peptide.polym.kyoto-u.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Ohmae
mesh_terms: D000118:Acetylglucosaminidase / Q000378:metabolism*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000096:biosynthesis* / Q000737:chemistry*; D055162:Biocatalysis; D006031:Glycosylation; D006801:Humans; D008968:Molecular Conformation; D010080:Oxazoles / Q000737:chemistry / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D010080:Oxazoles; D013431:Sulfates; C086950:keratanase II; D000118:Acetylglucosaminidase
keywords: Lewis X; enzyme catalysis; glycosylation; transition states; tumor-associated carbohydrate antigens