Glycosynthase-catalysed syntheses at pH below neutrality

Area of Science:

• Biocatalysis
• Enzymatic synthesis
• Glycochemistry

Background:

• Glycosynthases are enzymes that catalyze glycosidic bond formation.
• Efficient synthesis of complex carbohydrates is crucial for various applications.
• Understanding enzyme activity at different pH levels is important for optimizing biocatalytic processes.

Purpose of the Study:

• To report the use of a new glycosynthase (Ta-beta-GlyE386G) and a known one (Ss-beta-GlyE387G) for synthesizing specific disaccharides and galactosylation.
• To evaluate the enzymes' performance with low acceptor excesses.
• To demonstrate the applicability of enzymes' high activity at pH below neutrality.

Main Methods:

• Enzymatic synthesis using glycosynthases Ta-beta-GlyE386G and Ss-beta-GlyE387G.
• Synthesis of 4-methylumbelliferyl disaccharides.
• Galactosylation of alpha- and beta-xylosides of 4-penten-1-ol.
• Reaction optimization at pH below neutrality using 2-NP-based donors.

Main Results:

• Satisfactory reaction yields were achieved with low excesses of acceptors.
• Both enzymes demonstrated high activity at pH below neutrality.
• Successful transfer of glucose and galactose was observed from 2-nitrophenyl (2-NP)-based donors.

Conclusions:

• The novel glycosynthase Ta-beta-GlyE386G and Ss-beta-GlyE387G are effective tools for synthesizing valuable oligosaccharides.
• The enzymes' robust activity at acidic pH expands their utility in biocatalysis.
• These findings support the use of glycosynthases for efficient and selective carbohydrate synthesis.