A diterpene synthase from the sandfly <i>Lutzomyia longipalpis</i> produces the pheromone sobralene.

Abstract

The phlebotomine sandfly, <i>Lutzomyia longipalpis</i>, a major vector of the <i>Leishmania</i> parasite, uses terpene pheromones to attract conspecifics for mating. Examination of the <i>L. longipalpis</i> genome revealed a putative terpene synthase (TPS), which-upon heterologous expression in, and purification from, <i>Escherichia coli</i>-yielded a functional enzyme. The TPS, termed <i>Ll</i>TPS, converted geranyl diphosphate (GPP) into a mixture of monoterpenes with low efficiency, of which β-ocimene was the major product. (<i>E,E</i>)-farnesyl diphosphate (FPP) principally produced small amounts of (<i>E</i>)-β-farnesene, while (<i>Z,E</i>)- and (<i>Z,Z</i>)-FPP yielded a mixture of bisabolene isomers. None of these mono- and sesquiterpenes are known volatiles of <i>L. longipalpis</i>. Notably, however, when provided with (<i>E,E,E</i>)-geranylgeranyl diphosphate (GGPP), <i>Ll</i>TPS gave sobralene as its major product. This diterpene pheromone is released by certain chemotypes of <i>L. longipalpis</i>, in particular those found in the Ceará state of Brazil. Minor diterpene components were also seen as products of the enzyme that matched those seen in a sandfly pheromone extract.