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Ji Y, Sasmal A, Li W, Oh L, Srivastava S, Hargett AA, Wasik BR, Yu H, Diaz S, Choudhury B, Parrish CR, Freedberg DI, Wang LP, Varki A, Chen X. Reversible O-Acetyl Migration within the Sialic Acid Side Chain and Its Influence on Protein Recognition. ACS Chem Biol 2021; 16:1951-1960. [PMID: 33769035 DOI: 10.1021/acschembio.0c00998] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
O-Acetylation is a common naturally occurring modification of carbohydrates and is especially widespread in sialic acids, a family of nine-carbon acidic monosaccharides. O-Acetyl migration within the exocyclic glycerol-like side chain of mono-O-acetylated sialic acid reported previously was from the C7- to C9-hydroxyl group with or without an 8-O-acetyl intermediate, which resulted in an equilibrium that favors the formation of the 9-O-acetyl sialic acid. Herein, we provide direct experimental evidence demonstrating that O-acetyl migration is bidirectional, and the rate of equilibration is influenced predominantly by the pH of the sample. While the O-acetyl group on sialic acids and sialoglycans is stable under mildly acidic conditions (pH < 5, the rate of O-acetyl migration is extremely low), reversible O-acetyl migration is observed readily at neutral pH and becomes more significant when the pH increases to slightly basic. Sialoglycan microarray studies showed that esterase-inactivated porcine torovirus hemagglutinin-esterase bound strongly to sialoglycans containing a more stable 9-N-acetylated sialic acid analog, but these compounds were less resistant to periodate oxidation treatment compared to their 9-O-acetyl counterparts. Together with prior studies, the results support the possible influence of sialic acid O-acetylation and O-acetyl migration to host-microbe interactions and potential application of the more stable synthetic N-acetyl mimics.
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Affiliation(s)
- Yang Ji
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Aniruddha Sasmal
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Wanqing Li
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Lisa Oh
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Saurabh Srivastava
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Audra A. Hargett
- Laboratory of Bacterial Polysaccharides, Food and Drug Administration (FDA), Silver Spring, Maryland 20993, United States
| | - Brian R. Wasik
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, United States
| | - Hai Yu
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Sandra Diaz
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Biswa Choudhury
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Colin R. Parrish
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, United States
| | - Darón I. Freedberg
- Laboratory of Bacterial Polysaccharides, Food and Drug Administration (FDA), Silver Spring, Maryland 20993, United States
| | - Lee-Ping Wang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Ajit Varki
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Xi Chen
- Department of Chemistry, University of California, Davis, California 95616, United States
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Hanashima S, Ishikawa D, Akai S, Sato KI. Synthesis of the starfish ganglioside LLG-3 tetrasaccharide. Carbohydr Res 2009; 344:747-52. [PMID: 19281969 DOI: 10.1016/j.carres.2009.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 01/30/2009] [Accepted: 02/04/2009] [Indexed: 12/01/2022]
Abstract
The first synthesis of the ganglioside LLG-3 tetrasaccharide, which has attractive biological activities as well as a unique structure, is described. A C8-methoxy decorated sialic acid building block was initially prepared and a glycolic acid moiety was then introduced by sialylation. Amide condensation between the sialyl glycolic acid and an amino group at C5 on the sialyllactoside unit afforded the fully protected LLG-3 tetrasaccharide. Finally, the desired tetrasaccharide part of LLG-3 was obtained after careful global deprotection. [structure: see text].
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Affiliation(s)
- Shinya Hanashima
- Material and Life Chemistry, Faculty of Engineering, Kanagawa University, Yokohama, Kanagawa, Japan
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