Enzymatic syntheses of T antigen-containing glycolipid mimicry using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase.
Thomsen-Friedenreich antigen (T antigen) disaccharide, beta-D-galactose-(1-->3)-alpha-N-acetyl-D-galactosamine (beta-D-Gal-(1-->3)-alpha-D-GalNAc), containing glycolipid mimicry was synthesized using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase from Bacillus sp. This enzyme could transfer the disaccharide from a p-nitrophenyl substrate to water-soluble 1-alkanols and other alcohols at a transfer ratio of 70% or more. Although the transfer ratios were lower for water-insoluble than water-soluble alcohols, they were shown to increase by adding sodium cholate to the reaction mixtures. The enzyme also transferred the disaccharide directly from asialofetuin to 1-alkanols. The anomeric bond between the disaccharide and 1-alkanols of the transglycosylation product is in the alpha configuration as determined by sequential digestion of jack bean beta-galactosidase and Acremonium alpha-N-acetylgalactosaminidase. Since the transglycosylation product, beta-D-Gal-(1-->3)-alpha-D-GalNAc-(1-->O)-hexyl, efficiently inhibits the binding of anti-T antigen monoclonal antibody to asialofetuin, it has potential as an agent for blocking T antigen-mediated cancer metastasis.
Laboratory of Molecular Biology of Bioresponse, Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Japan. byd01621@nifty.ne.jp
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D000438:Alcohols; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000937:Antigen-Antibody Reactions / Q000187:drug effects; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000096:biosynthesis*; D000970:Antineoplastic Agents / Q000138:chemical synthesis; D001212:Asialoglycoproteins / Q000737:chemistry / Q000276:immunology; D001407:Bacillus / Q000201:enzymology; D001426:Bacterial Proteins / Q000378:metabolism*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003902:Detergents / Q000494:pharmacology; D004187:Disaccharides / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D015195:Drug Design; D004797:Enzyme-Linked Immunosorbent Assay; D060748:Fetuins; D038983:Galactolipids; D006017:Glycolipids / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D006031:Glycosylation; D006596:Hexosaminidases / Q000378:metabolism*; D013058:Mass Spectrometry; D051379:Mice; D018716:Molecular Mimicry; D011499:Protein Processing, Post-Translational; D020358:Sodium Cholate / Q000494:pharmacology; D012995:Solubility; D012997:Solvents; D014867:Water; D000509:alpha-Fetoproteins / Q000737:chemistry / Q000276:immunology; D048809:alpha-N-Acetylgalactosaminidase
D000438:Alcohols; D000911:Antibodies, Monoclonal; D015295:Antigens, Tumor-Associated, Carbohydrate; D000970:Antineoplastic Agents; D001212:Asialoglycoproteins; D001426:Bacterial Proteins; D003902:Detergents; D004187:Disaccharides; D060748:Fetuins; D038983:Galactolipids; D006017:Glycolipids; D012997:Solvents; D000509:alpha-Fetoproteins; C017029:asialofetuin; C430205:galactopyranosyl-1-3-N-acetylgalactosamine hexyl glycoside; D014867:Water; C016467:Thomsen-Friedenreich antigen; D006596:Hexosaminidases; D048809:alpha-N-Acetylgalactosaminidase; D020358:Sodium Cholate