Probing the role of polyphenol oxidation in mediating insect-pathogen interactions.: Galloyl-derived electrophilic traps for the Lymantria dispar nuclear polyhedrosis virus matrix protein polyhedrin

Galloyl-derived orthoquinone probes have been designed, synthesized, and utilized in an ongoing study of insect-pathogen interactions. A stable galloyl-derived orthoquinone O-methyl ether modified with both acidic and fluorescent appendages was successful in trapping the model nucleophile cysteine, a test protein bearing a single cysteine residue, and the viral occlusion body matrix protein polyhedrin from Lymantria dispar nuclear polyhedrosis virus (LdNPV), a pathogen of the gypsy moth caterpillar (GMc). This latter observation may be related to the molecular mechanism by which gallotannins decrease LdNPV infectivity in GMc's. Sufficient site isolation was not achieved with a polymer-bound reactive galloyl hydroxyorthoquinone electrophile to permit similar nucleophile trapping to compete with oligomerization.