Abstract:
The phlebotomine sandfly, Lutzomyia longipalpis, a major vector of the Leishmania parasite, uses terpene pheromones to attract conspecifics for mating. Examination of the L. longipalpis genome revealed a putative terpene synthase (TPS), which-upon heterologous expression in, and purification from, Escherichia coli-yielded a functional enzyme. The TPS, termed LlTPS, converted geranyl diphosphate (GPP) into a mixture of monoterpenes with low efficiency, of which β-ocimene was the major product. (E,E)-farnesyl diphosphate (FPP) principally produced small amounts of (E)-β-farnesene, while (Z,E)- and (Z,Z)-FPP yielded a mixture of bisabolene isomers. None of these mono- and sesquiterpenes are known volatiles of L. longipalpis. Notably, however, when provided with (E,E,E)-geranylgeranyl diphosphate (GGPP), LlTPS gave sobralene as its major product. This diterpene pheromone is released by certain chemotypes of L. longipalpis, 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.
摘要:
静脉沙蝇,Lutzomialongialpis,利什曼原虫寄生虫的主要媒介,使用萜烯信息素来吸引交配。对Longipalpis乳杆菌基因组的检查显示了一种推定的萜烯合酶(TPS),在异源表达时,和净化,大肠杆菌产生了一种功能性酶。TPS,称为LTPS,以低效率将二磷酸香叶酯(3GPP)转化为单萜的混合物,其中β-辛烯是主要产物。(E,E)-法尼基二磷酸(FPP)主要产生少量(E)-β-法尼烯,而(Z,E)-和(Z,Z)-FPP产生了双代谢物异构体的混合物。这些单萜和倍半萜都不是L.longipalpis的已知挥发物。值得注意的是,然而,当提供(E,E,E)-香叶基香叶基二磷酸(G3GPP),LTPS给出索布拉烯作为其主要产物。这种二萜信息素是由龙氏乳杆菌的某些化学型释放的,特别是在巴西塞阿拉州发现的那些。次要的二萜成分也被视为与沙蝇信息素提取物中看到的那些相匹配的酶的产物。