EXPRESSION AND CHARACTERIZATION OF THE RECOMBINANT JUVENILE-HORMONE EPOXIDE HYDROLASE (JHEH) FROM MANDUCA-SEXTA

The cDNA of the microsomal Juvenile Hormone Epoxide Hydrolase (JHEH) f rom Manduca sexta was expressed in vitro in the baculovirus system. In insect cell culture, the recombinant enzyme (Ms-JHEH) was produced at a high level (100 fold over background EH catalytic activity). As exp ected, Ms-JHEH was localized in the microsomal fraction with a molecul ar mass of approximately 50 kDa. Ms-JHEH showed a substrate and inhibi tor spectrum similar to the wild type JHEH isolated from eggs of M. se xta. Its enzymatic activity was the highest for Juvenile Hormone III. Ms-JHEH hydrolyzed several trans-epoxides faster than cis-epoxides. A putative hydroxyl-acyl enzyme intermediate was isolated suggesting a c atalytic mechanism of Ms-JHEH similar to the mammalian EHs. (C) 1998 E lsevier Science Ltd. All rights reserved.