Purification and Functional Characterization of a Soluble Trehalase in (Coleoptera: Curculionidae).

Trehalase is the only enzyme known for the irreversible splitting of trehalose and plays a major role in insect growth and development. In this report, we describe a basic study of the trehalase gene fragment encoding a soluble trehalase from (). Sequence alignment and phylogenetic analysis suggested that was similar to some known insect trehalases and belongs to the Coleoptera trehalase group. Additionally, was expressed mainly in the fat body. Purified protein was obtained using heterologous expression of in , and the recombinant protein exhibited the ability to decompose trehalose. Enzyme-substrate docking indicated the potential involvement of other residues in the catalytic activity, in addition to Asp 333. Moreover, feeding of adults on dsRNA silenced the transcription of and thereby reduced the activity of trehalase and increased the trehalose content; it also led to a 12% death rate. This study reveals essential molecular features of trehalase and offers insights into the structural aspects of this enzyme, which might be related to its function. Taken together, the findings demonstrate that is indispensable for adults of this pest and provide a new target for the control of .