담배거세미나방(Spodoptera litura) 유충 혈림프의 Phenoloxidase효소계

Phenoloxidase System in the Haemolymph of Spodoptera litura Larvae

During studies of non-self recognition in insects, we began an analysis of the phenoloxidase(PO) system from the larval haemolymph of Spodoptera litura PO is present in haemolymph and proPO can be activated by organic solvents or heat treatment. Phenoloxidase activity has been determined using phenolic substrates. The enzyme catalysed the oxidation of other di-phenols besides dopa but not the monophenol tyrosine, even in the presence of a catalytic amount of dopa. It was also found that incubation of haemolymph with aceton, certain alcohols, served to induce enzyme activity. The enzyme has been localized in the 7% slab and disc PAGE as an intense band with high molecular weight. Other experiments included determination of the Michaelis constants for dopa, and determination of the effects of temperature and thermostability, and pH dependence on the phenoloxidase system. The enzyme is suggested to be involved in wound healing.