Identification of a novel carboxylesterase dominantly expressed in the booklouse, Liposcelis bostrychophila

Abstract

Booklice are tiny insect pests commonly found indoors and characterized by high proliferation ability. Booklice contamination in stored foods causes profound food loss and possibly allergic reactions after ingestion; thus, booklice are known as stored-food pests. Therefore, the safe extermination of booklice would solve food loss and allergic concerns. Organophosphates (OPs) are used as harmless insecticides against various pests; nonetheless, cases of OP poisoning are reported worldwide. Therefore, considering protecting stored-food products, OP doses should be minimal. It is generally known that carboxylesterase-mediated inactivation of OPs decreases the efficacy of OPs, suggesting that an inhibitor of carboxylesterase could be a synergist in reducing the effective dose of OP. Herein, I report the molecular cloning of a novel carboxylesterase dominantly expressed in a representative species of indoor booklice, Liposcelis bostrychophila, designated Liposcelis bostrychophila carboxylesterase 1 (LBCE1). The recombinant protein of LBCE1 was shown to have an elastase activity. Furthermore, using the 3D-structural model of LBCE1, its possible binding to OP insecticides was predicted in silico. These results suggest that a specific LBCE1 inhibitor may serve as a synergist to better control booklice.