Fluorinating the Sugar and the Nucleotide: Exploring Fluorination Within GDP-Mannose Probes Using Chemoenzymatic...

Area of Science:

• Carbohydrate Chemistry and Chemical Biology
• Glycobiology and Glycochemistry
• Enzymology and Metabolic Engineering

Background:

• Fluorinated glycans are valuable tools for studying protein-glycan interactions, enzymatic stability, and physicochemical properties.
• Sugar nucleotides, like GDP-mannose, are essential precursors for glycan synthesis, offering a target for fluorination.
• Understanding the structure-function relationships of glycan biosynthesis is crucial for various biological processes.

Purpose of the Study:

• To develop a chemoenzymatic approach for incorporating fluorine into the GDP-mannose framework.
• To create novel fluorinated GDP-mannose analogs for studying glycosyltransferases.
• To investigate the role of GDP-mannose in the alginate biosynthesis pathway of *Pseudomonas aeruginosa*.

Main Methods:

• Chemical synthesis was employed to introduce specific fluorine modifications into the nucleoside diphosphate sugar.
• A promiscuous pyrophosphorylase enzyme was utilized for the assembly of the fluorinated sugar nucleotide.
• The synthesized fluorinated GDP-mannose analogs were used to probe guanosine diphosphate mannose dehydrogenase activity.

Main Results:

• First-in-class synthesis of GDP-mannose analogs featuring fluorine within the pyranose ring and the nucleotide moiety.
• Demonstrated the utility of these fluorinated analogs in studying enzymes involved in glycan biosynthesis.
• Provided insights into the guanosine diphosphate mannose dehydrogenase critical for *Pseudomonas aeruginosa* alginate production.

Conclusions:

• This work establishes a versatile framework for synthesizing fluorinated sugar nucleotides, expanding the toolkit for glycobiology research.
• The developed fluorinated GDP-mannose analogs enable detailed studies of GDP-mannose-utilizing glycosyltransferases.
• This approach facilitates structure-to-function analyses of glycan biosynthesis pathways and enzyme mechanisms.