Fructoselyases

Fructoselyases are a group of enzymes that catalyze the transfer of a fructosyl group from a donor molecule to an acceptor molecule. These enzymes are primarily known for their role in carbohydrate metabolism, particularly in the synthesis and breakdown of sucrose and related oligosaccharides. The most well-studied fructoselyases are sucrose synthase and fructosyltransferase.

Sucrose synthase (EC 2.4.1.13) plays a crucial role in sucrose metabolism in plants and bacteria. It catalyzes the reversible reaction between sucrose and UDP-glucose or ADP-glucose to form fructose and UDP-fructose or ADP-fructose, respectively. This enzyme is important for both sucrose synthesis and the utilization of sucrose as an energy source.

Fructosyltransferases (EC 2.4.1.9) are responsible for the synthesis of fructans, which are polymers of fructose. These enzymes can transfer fructosyl units from sucrose to a growing fructan chain or to another sucrose molecule, leading to the formation of various fructan structures, such as inulin and levan. Fructans serve as storage carbohydrates in many plants and are also found in some bacteria.

The activity of fructoselyases is influenced by factors such as pH, temperature, and the presence of specific ions. They have industrial applications, including in the production of high-fructose corn syrup and the synthesis of specialty oligosaccharides for functional food ingredients. Research continues to explore the diverse functions and potential applications of this enzyme family.