Mechanism of action and cloning of epoxide hydrolase from the cabbage looper, Trichoplusia ni.
The majority of the JH III epoxide hydrolase activity in last stadium day 3 (gate 1) wandering Trichoplusia ni was membrane bound with approximately 9% of the activity found in the cytosol. Both the microsomal and cytosolic JH epoxide hydrolases were stable, retaining 30% of their original activity after incubation at 4 degrees C for 15 days. 18O-labeled water underwent enzyme catalyzed regioselective addition to the least substituted C10 position of JH III. In multiple turnover reactions with JH epoxide hydrolase in 97.9% 18O-labeled water, only 91.3% 18O incorporation was observed. This is consistent with an SN2 reaction likely involving a carboxylate in the active site of JH epoxide hydrolase. The DNA amplification cloning of a fragment of a putative T. ni epoxide hydrolase is reported. The deduced amino acid sequence shares 67% similarity to the rat microsomal epoxide hydrolase.
Roe
R M
RM
Department of Entomology, North Carolina State University, Raleigh 27695-7647, USA.
Kallapur
V
V
Linderman
R J
RJ
Viviani
F
F
Harris
S V
SV
Walker
E A
EA
Thompson
D M
DM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003600:Cytosol / Q000201:enzymology; D004247:DNA; D004851:Epoxide Hydrolases / Q000235:genetics* / Q000378:metabolism*; D005784:Gene Amplification; D008861:Microsomes / Q000201:enzymology; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology*
D004247:DNA; D004851:Epoxide Hydrolases; C055698:juvenile hormone epoxide hydrolase