The cytosolic trehalase enzyme, NT, has been purified and characterized extensively from S. cerevisiae. In non-denaturing gels this enzyme protein exhibited a molecular mass of 160 kDa, while in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) it showed a mass of 80 kDa4. This hydrolase enzyme is specific for trehalose. The Km of NT has been reported to be 5.7mM. The gene responsible for trehalase activity in S. cerevisiae is NTH1. 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.
NT activity is regulated by protein phosphorylation-dephosphorylation. Phosphorylation with cAMP-dependent protein kinase activates NT. Dephosphorylation of the purified phosphorylated enzyme by alkaline phosphatase caused an almost complete inactivation of the enzyme activity; but a recovery of the enzyme activity could be observed by rephosphorylation while incubating with ATP and protein kinase. The activity of NT in crude extracts is enhanced by polycations, while the activity of purified phosphorylated NT is inhibited by them. The activation of crude extracts was found to be due to the removal of polyphosphates, both of which inhibit NT activity.