Development of an HTS assay for EPHX2 phosphatase activity and screening of nontargeted libraries

作者：Morisseau Christophe; Sahdeo Sunil; Cortopassi Gino; Hammock Bruce D

来源：Analytical Biochemistry, 2013, 434(1): 105-111.

DOI：10.1016/j.ab.2012.11.017

• Soluble epoxide hydrolase
• HIS assay
• Phosphatase
• Ebselen

The EPXH2 gene encodes soluble epoxide hydrolase (sEH), which has two distinct enzyme activities: epoxide hydrolase (Cterm-EH) and phosphatase (Nterm-phos). The Cterm-EH is involved in the metabolism of arachidonic acid epoxides that play important roles in blood pressure, cell growth, inflammation, and pain. While recent findings suggested complementary biological roles for Nterm-phos, research is limited by the lack of potent bioavailable inhibitors of this phosphatase activity. Also, a potent bioavailable inhibitor of this activity could be important in the development of therapy for cardiovascular diseases. We report herein the development of an HTS enzyme-based assay for Nterm-phos (Z' > 0.9) using AttoPhos as the substrate. This assay was used to screen a wide variety of chemical entities, including a library of known drugs that have reached through clinical evaluation (Pharmakon 1600), as well as a library of pesticides and environmental toxins. We discovered that ebselen inhibits sEH phosphatase activity. Ebselen binds to the N-terminal domain of sEH (K-I = 550 nM) and chemically reacts with the enzyme to quickly and irreversibly inhibit Nterm-phos, and subsequently Cterm-EH, and thus represents a new class of sEH inhibitor.

• 出版日期2013-3-1