Identification of a juvenile hormone esterase gene by matching its peptidemass fingerprint with a sequence from the Drosophila genome project

Juvenile hormone esterase (JHE, EC 3.1.1.1) from whole Drosophila melanogas ter prepupae has previously been purified by selective precipitations, isoe lectric focussing and two column chromatography steps. JHE bands from dried silver-stained SDS-PAGE gels of that material were digested with trypsin. The masses of the tryptic digest peptides were determined by MALDI-TOF mass spectrometry. Only one predicted gene product (CG8425) from the D. Melanog aster genome matches the JHE tryptic fingerprint with high confidence. This predicted JHE sequence includes features that are conserved among all acti ve members of the serine carboxylesterase multigene family as well as featu res peculiar to JHEs from other species. Also we show that this JHE can be purified by an alternative method using anion exchange chromotography follo wed by trifluoromethylketone affinity chromatography. A cDNA encoding this JHE was isolated using 3' and 5' RACE. This sequence is in agreement with t he Drosophila genome project's prediction except that the sixth predicted i ntron is not removed, instead there is a stop codon followed by a polyadeny lation signal and a polyA tail. (C) 2001 Elsevier Science Ltd. All rights r eserved.