The enzyme juvenile hormone esterase (EC 3.1.1.59, systematic name methyl-(2E,6E,10R)-10,11-epoxy-3,7,11-trimethyltrideca-2,6-dienoate acylhydrolase, JH esterase) catalyzes the hydrolysis of juvenile hormone: This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds.
[3] The drop in JH titer at the beginning of the last larval instar in the Lepidoptera appears to be due to a combination of increased metabolism [4] and decreased synthesis.
[8] These studies suggest that the JHE's may be important in the regulation of the JH titre and therefore involved in the initiation of and the commitment to the pupal stage.
[10] Stimulation of JHE activity by JH has also been noted recently in adults of Leptinotarsa decemlineata [11] and pupae of Galleria mellonella.
[12] However, to date, no reported studies have examined this phenomenon during the last larval instar when these enzymes are thought to be of primary importance.
Thus this laboratory undertook an investigation of the hemolymph JHE regulation during the last larval instar of the cabbage looper, Trichoplusia ni.
Juvenile hormone esterase is induced by factors naturally occurring in the head of insects.
[15] In another study, it has been shown that factors present in the head of the insect are potent inducers of JH activity.
Of particular interest in this study is that ethyl and isopropyl analogs of natural JHs were NOT cleaved by the esterase, showing that it is methyl ester specific.
There is a large peak of JH I and II at the end of the fourth stadium, accompanied by lower levels of their acid metabolites.
[21] A very similar timing of peaks of JH esterase and ecdysone has been observed in Galleria mellonella.
[23] However, secretion of the relative amounts of JH produced by CA of Manduca sexta has been found to differ considerably from in vivo titers.
[25] The crystal structure of esterase from the tobacco hornworm Manduca sexta has been solved in complex with the transition state analogue inhibitor 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP) covalently bound to the active site.
This crystal structure contains a long, hydrophobic binding pocket with the solvent-inaccessible catalytic triad located at the end.
Kinetic properties of the inhibition juvenile hormone esterase by two trifluoromethylketones and O-ethyl, S-phenyl phosphoramidothioate.
Influence of Hemolymph-Binding Protein on Juvenile-Hormone Stability and Distribution in Manduca Sexta Fat-Body and Imaginal Disks In vitro.
Correlations between Juvenile Hormone Esterase-Activity, Ecdysone Titer and Cellular Reprogramming in Galleria Mellonella.
The Juvenile Hormone Titre During the Penultimate and Ultimate Larval Stadia of Trichoplusia ni.
The source and action of head factors regulating juvenile hormone esterase in larvae of the cabbage looper, Trichoplusia ni.
Regulation of the activity of JH-specific esterases in the Colorado potato beetle, Leptinotarsa decemlineata.
Control of Moulting and Metamorphosis in the Tobacco Hornworm, Manduca Sexta (L.): Cessation of Juvenile Hormone Secretion as a Trigger for Pupation J. Exp.
Dynamics of juvenile hormone action in larvae of the tobacco horn worm.
In vitro analysis of factors regulating the juvenile hormone titer of insects, in: Kurstack, E., Maramorosch, K.
A juvenile hormone binding protein from the house fly and its possible relationship to insecticide resistance.
Factors Influencing Juvenile Hormone Esterase-Activity in the Wax Moth, Galleria-Mellonella.
Juvenile hormone acid methyltransferase activity in imaginal discs of Manduca sexta prepupae.
Induction and regulation of juvenile hormone esterases during the last larval instar of the cabbage looper, Trichoplusia ni.
Effects of the anti hormone-hormone mimic ETB on the induction of insect juvenile hormone esterase in Trichoplusia ni.
Juvenile hormone esterase activity in precisely timed last instar larvae and pharate pupae of Manduca sexta.
Structural Studies of a Potent Insect Maturation Inhibitor Bound to the Juvenile Hormone Esterase of Manduca sexta.