Transglycosylation reactions catalysed by two beta-mannanases

Area of Science:

• Biochemistry
• Enzymology
• Carbohydrate Chemistry

Background:

• Beta-mannanases are enzymes that degrade beta-mannans, important components of plant cell walls.
• Understanding the catalytic mechanisms of different beta-mannanases is crucial for applications in biotechnology and biofuel production.

Purpose of the Study:

• To investigate and compare the transferase activities of two distinct beta-mannanases.
• To characterize the products of transfer reactions catalyzed by Streptomyces and fenugreek beta-mannanases.

Main Methods:

• Enzymatic assays using [3H]mannobiose as a labeled acceptor molecule.
• Substrates included mannotetraose and mannopentaose oligosaccharides.
• Analysis of reaction products to determine the extent of mannose transfer.

Main Results:

• Both beta-mannanases catalyzed transfer reactions, indicating transglycosylation activity.
• The beta-mannanase from Streptomyces transferred a single mannose unit to the acceptor.
• The beta-mannanase from fenugreek (Trigonella foenum-graecum) transferred oligomannose residues.

Conclusions:

• Different beta-mannanases exhibit distinct substrate specificities and transfer mechanisms.
• The fenugreek enzyme shows potential for synthesizing larger manno-oligosaccharides through transglycosylation.