The Purification and Some Properties of Soluble Trehalase and Sucrase from Drosophila melanogaster

Abstract

Soluble trehalase (EC 3.2.1.28) from Drosophila melanogaster was purified to a specific activity of about 112 units/mg and only one band was detected by analytical disc-gel electrophoresis. Soluble sucrase (EC 3.2.1.26) having a specific activity of about 10 units/mg was obtained. The two enzymes had similar molecular weights, pH optima, and responses to mercaptoethanol, and neither enzyme was activated by ions or ethanol. Para-chloromercuribenzoate inhibited sucrase to a greater extent than trehalase while iodoacetate did not affect either enzyme. Sucrase was less stable to a variety of denaturing conditions, the Km's of the two enzymes differed greatly, and Tris and Tricine were much stronger competitive inhibitors of sucrase than of trehalase. Both enzymes underwent a large reduction in molecular weight during the purification procedure.