Details

Autor(en) / Beteiligte

• Almaraz, Ruben T.
• Aich, Udayanath
• Khanna, Hargun S.
• Tan, Elaine
• Bhattacharya, Rahul
• Shah, Shivam
• Yarema, Kevin J.

Titel

Metabolic oligosaccharide engineering with N-Acyl functionalized ManNAc analogs: Cytotoxicity, metabolic flux, and glycan-display considerations

Ist Teil von

• Biotechnology and bioengineering, 2012-04, Vol.109 (4), p.992-1006

Ort / Verlag

Hoboken: Wiley Subscription Services, Inc., A Wiley Company

Erscheinungsjahr

2012

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Metabolic oligosaccharide engineering (MOE) is a maturing technology capable of modifying cell surface sugars in living cells and animals through the biosynthetic installation of non‐natural monosaccharides into the glycocalyx. A particularly robust area of investigation involves the incorporation of azide functional groups onto the cell surface, which can then be further derivatized using “click chemistry.” While considerable effort has gone into optimizing the reagents used for the azide ligation reactions, less optimization of the monosaccharide analogs used in the preceding metabolic incorporation steps has been done. This study fills this void by reporting novel butanoylated ManNAc analogs that are used by cells with greater efficiency and less cytotoxicity than the current “gold standard,” which are peracetylated compounds such as Ac4ManNAz. In particular, tributanoylated, N‐acetyl, N‐azido, and N‐levulinoyl ManNAc analogs with the high flux 1,3,4‐O‐hydroxyl pattern of butanoylation were compared with their counterparts having the pro‐apoptotic 3,4,6‐O‐butanoylation pattern. The results reveal that the ketone‐bearing N‐levulinoyl analog 3,4,6‐O‐Bu3ManNLev is highly apoptotic, and thus is a promising anti‐cancer drug candidate. By contrast, the azide‐bearing analog 1,3,4‐O‐Bu3ManNAz effectively labeled cellular sialoglycans at concentrations ∼3‐ to 5‐fold lower (e.g., at 12.5–25 µM) than Ac4ManNAz (50–150 µM) and exhibited no indications of apoptosis even at concentrations up to 400 µM. In summary, this work extends emerging structure activity relationships that predict the effects of short chain fatty acid modified monosaccharides on mammalian cells and also provides a tangible advance in efforts to make MOE a practical technology for the medical and biotechnology communities. Biotechnol. Bioeng. 2012; 109:992–1006. © 2011 Wiley Periodicals, Inc. Per‐acetylated N‐azido‐mannosamine (Ac4ManNAz) is a widely used metabolic substrate for labeling sialic acids in living cells and animals. In this work the authors show that n‐butanoylated ManNAz can achieve higher flux through the sialic acid biosynthetic pathway and highlight structure‐activity relationships where tributanoylated analog with the “3,4,6” pattern of butyrate derivation is highly toxic while the corresponding “1,3,4” analog has negligible toxicity and thus serves as an optimal molecular tool for incorporating azide groups into cellular sialoglycans.