Trehalose

Trehalose

Chemical structure of trehalose

Trehalose is a disaccharide consisting of two glucose molecules linked by an _,_-1,1-glycosidic bond. It is a naturally occurring sugar found in various organisms, including bacteria, fungi, plants, and invertebrates. Trehalose is known for its ability to protect cells from stress conditions such as desiccation, freezing, and osmotic pressure.

Structure and Properties

Trehalose is composed of two _-D-glucose units. The unique _,_-1,1 linkage distinguishes it from other disaccharides like maltose, which has an _-1,4 linkage. This structure contributes to its non-reducing nature, making it more stable under heat and acidic conditions. Trehalose is highly soluble in water and has a mild sweetness, approximately 45% that of sucrose.

Biological Role

Trehalose serves as an important source of energy and carbon in many organisms. It plays a crucial role in anabiosis, allowing organisms to survive extreme dehydration. In yeast and fungi, trehalose acts as a reserve carbohydrate, while in insects, it is the primary blood sugar. The sugar is also involved in the stabilization of proteins and cellular membranes during stress.

Industrial Applications

Due to its stability and non-reducing nature, trehalose is used in the food industry as a sweetener and stabilizer. It is also employed in the pharmaceutical and cosmetic industries for its ability to protect biological structures. Trehalose is used in the preservation of biological samples, vaccines, and enzymes.

Synthesis

Trehalose can be synthesized by several enzymatic pathways. In bacteria and yeast, the most common pathway involves the enzyme trehalose-6-phosphate synthase, which catalyzes the formation of trehalose-6-phosphate from glucose-6-phosphate and UDP-glucose. This intermediate is then dephosphorylated to produce trehalose.

Health and Safety

Trehalose is generally recognized as safe (GRAS) by the Food and Drug Administration (FDA) and is used in various food products. However, some studies have suggested that high levels of trehalose consumption may be linked to the proliferation of certain Clostridium difficile strains, although more research is needed to fully understand this relationship.

Related Pages

• Disaccharide
• Glucose
• Carbohydrate
• Anabiosis