The enzyme Trehalase is a glycoside hydrolase, produced by cells in the brush border of the small intestine, which catalyzes the conversion of trehalose to glucose.

The non-reducing disaccharide trehalose (α-D-glucopyranosyl-1,1-α-D-glucopyranoside) is one of the most important storage carbohydrates, and is produced by almost all forms of life except mammals.

Since then the trehalose hydrolyzing enzyme, trehalase (α, α-trehalose-1-C-glucohydrolase, EC 3.2.1.28) has been reported from many other organisms including plants and animals.

Individuals with a defect in their intestinal trehalase have diarrhea when they eat foods with high trehalose content, such as mushrooms.

[6] Trehalose hydrolysis by trehalase enzyme is an important physiological process for various organisms, such as fungal spore germination, insect flight, and the resumption of growth in resting cells.

[6] Trehalose has been reported to be present as a storage carbohydrate in Pseudomonas, Bacillus, Rhizobium and in several actinomycetes and may be partially responsible for their resistance properties.

In plant kingdom, though trehalose has been reported from several pteridophytes including Selaginella lepidophylla and Botrychium lunaria; the sugar is rare in vascular plants and reported only in ripening fruits of several members of Apiaceae and in the leaves of the desiccation-tolerant angiosperm Myrothamnus flabellifolius.

This gene is with an open reading frame of 2079 base pairs (bp), encoding a protein of 693 amino acids, corresponding to a molecular mass of 79569 Da.

The 41 kDa carbohydrate free protein moiety of the enzyme was obtained by Endoglycosidase H treatment of purified AT, resulted after sodium dodecyl sulfate gel electrophoresis27.

Researchers have suggested that AT moves from its site of synthesis to the periplasmic space, where it binds exogenous trehalose to internalize it and hydrolyze it in the vacuoles.

Recently it has been shown that more than 90% of AT activity in S. cerevisiae is extracellular and the hydrolysis of trehalose into glucose takes place at the periplasmic space.

Previously, a highly glycosylated protein, gp37, which is the product of YGP1 gene, was reported to be co-purified with AT activity.

These two enzymes were reported to be distinguishable by their molecular weight, behavior in ion-exchange chromatography and kinetic properties.