Human CES2 peptide

Diphenidol is an important drug clinically used to treat ENT (ear, nose, throat) diseases. So far, no adverse effects have been reported. The present study aims to investigate the adverse effects of diphenidol through determining the inhibition of diphenidol on the activity of carboxylesterases (CES), including CES1 and CES2. In vitro human liver microsomes (HLMs)-catalyzed hydrolysis of 2-(2-benzoyl-3-methoxyphenyl) benzothiazole (BMBT) was used to determine the inhibition of diphenidol on the activity of CES1. In vitro HLMs-catalyzed hydrolysis of fluorescein diacetate (FD) was used to determine the inhibition of diphenidol on CES2. Diphenidol 100 mu M was used as the initial screening concentration. Diphenidol 100 mu M did not show inhibitory on the activity of CES1. In the contrast, 100 mu M of diphenidol inhibited 75% activity of CES2 (p < 0.001). In conclusion, high attention should be given for drug-drug interaction between diphenidol and drugs mainly undergoing CES-catalyzed hydrolysis metabolism.

The purpose of this study was to develop an analytical method to quantify the relative activities of carboxylesterases (CESs) in biological samples. Taking the advantage of loperamide, a specific carboxylesterase 2 (CES2) inhibitor, and bis-p-nitrophenyl phosphate (BNPP), an irreversible CESs inhibitor, we propose for the first time a capillary electrophoresis (CE) method that enables detecting and distinguishing CES2 activity from Other CESs in complex biological samples. The Capillary electrophoresis method proved to be fist, simple, repeatable, and applicable to the measurement of the specific activity of CESs. The method was successfully applied to the evaluation of human cells overexpressing human carboxylesterase 2 (hCE-2) and to several mammalian sera, using extremely small amounts of samples in comparison with traditional spectrophotometric methods. The same rationale can be applied to establish methods for determining the activity of other isoenzymes, using the appropriate specific inhibitors.