Enzymatic and insecticidal activities of the Amsacta moorei entomopoxvirus glycosyltransferase, AMV248

The family Poxviridae is divided into two subfamilies, the Chordopoxvirinae of vertebrates and the Entomopoxvirinae of invertebrates. The Amsacta moorei entomopoxvirus (AMEV, Entomopoxvirinae) has the potential to be used in gene therapy, as an expression vector, and as a biopesticide. It was suggested that AMV248 protein is a putative glycosyltransferase (GT) but was also shown to be an attachment protein to host receptors. GTs encoded by some other viruses catalyse the binding of sugars molecules to growth hormones of the host insects rendering the hormones inactive. Consequently, larval development is arrested and frequently results in larval mortality. In this study, AMV248 protein was shown to be a GT and the purified enzyme catalysed the production of uridine diphosphate (UDP) from the substrates UDP-glucose and UDP-N-acetylglucosamine. This AMEV enzyme may behave much like the ecdysteroid UDP-glucosyltransferase of baculoviruses. Various concentrations of the GT enzyme were tested for its insecticidal activity against gypsy moth Lymantria dispar (Linnaeus, 1758) (Lepidoptera: Lymantriidae), lackey moth Malacosoma neustria (Linnaeus, 1758) (Lepidoptera: Lasiocampidae), cotton bollworm Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) and the greater wax moth Galleria mellonella (Linnaeus, 1758) (Lepidoptera: Pyralidae) larvae. It had varying deleterious effects on all test larvae but L. dispar was the most sensitive to the enzyme. While this enzyme exhibits properties with potential to be developed as an insecticide in biocontrol strategies, investigations are needed to ascertain its value in pest management.