Repurposing CDP-Tyvelose 2‑Epimerase Enables a GDP-Fucose-Based Fucosylation Pathway Starting from Sucrose

Area of Science:

• Biocatalysis
• Glycochemistry
• Enzymology

Background:

• Fucosylated glycosides are important in biological processes.
• Efficient and scalable synthesis methods are needed.

Purpose of the Study:

• To develop a novel enzymatic cascade for synthesizing fucosylated glycosides.
• To utilize sucrose exclusively as the sugar donor substrate.

Main Methods:

• A five-enzyme cascade was engineered using recombinant enzymes.
• Enzymes included sucrose synthase, CDP-tyvelose 2-epimerase, GDP-mannose 4,6-dehydratase, GDP-4-keto-6-deoxy-d-mannose epimerase/reductase, and α1,3-fucosyltransferase.
• Sucrose was used as the sole sugar donor.

Main Results:

• The cascade efficiently synthesized GDP-glucose, GDP-mannose, and GDP-l-fucose from sucrose.
• para-nitrophenyl β-lactoside was fucosylated to produce para-nitrophenyl 3-fucosyllactoside with >40% conversion.
• Product structure was confirmed by LC-MS and NMR.

Conclusions:

• The five-enzyme cascade provides an efficient biocatalytic route to fucosylated glycosides.
• This methodology offers a novel paradigm for producing α-l-fucosides for research and biotechnological applications.