Mechanism of action and cloning of epoxide hydrolase from the cabbage looper, Trichoplusia ni

✍ Scribed by R. Michael Roe; Vasant Kallapur; Russell J. Linderman; Fabrice Viviani; Shannon V. Harris; Elizabeth A. Walker; Deborah M. Thompson

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 577 KB
• Volume: 32
• Category: Article
• ISSN: 0739-4462
• DOI: 10.1002/(sici)1520-6327(1996)32:3/4<527::aid-arch24>3.0.co;2-d

✦ Synopsis

The majority of the JH Ill 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 J H epoxide hydrolases were stable, retaining 30% of their original activity after incubation at 4°C for 15 days. "0-labeled water underwent enzyme catalyzed regioselective addition to the least substituted C10 position of JH Ill. In multiple turnover reactions with JH epoxide hydrolase in 97.9% '%-labeled water, only 91.3% " 0 incorporation was observed. This is consistent with an Sh2 reaction likely involving a carboxylate in the active site of J H 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?L similarity to the rat microsomal epoxide hydrolase. o 1996 Wiley-Liss, Inc.