Pig Liver Cytosolic Carboxylesterase 1 and Its Inhibition by Remdesivir and Sofosbuvir

Abstract

Pig carboxylesterases (CESs) are recognized as enzymes that metabolize xenobiotics, and many drugs used in pig breeding that contain ester groups can be hydrolyzed by CESs. However, there are a limited number of publications focused on the molecular weight, inhibitor effects, and enzyme kinetics of porcine cytosolic carboxylesterase. This study presents the first investigation of the presence, kinetics, inhibition, and amino acid sequence of CES1, the major cytosolic CES isozyme in pig liver. The molecular weight of pig liver cytosolic CES1 was estimated to be approximately 179 kDa, and the amino acid sequence of the enzyme subunit was determined. The inhibition of CES1 by the antiviral drugs remdesivir and sofosbuvir was studied, and the IC50 values were determined. The results indicate that remdesivir and sofosbuvir can act as potent modulators of CES1. The inhibitors exhibited mixed‐type inhibition on pig liver cytosol CES1. It was found that the affinity of the remdesivir and sofosbuvir for free enzyme is greater than that for the enzyme‐substrate complex. A spectrofluorimetric method confirmed the inhibition findings, as the fluorescence intensity of remdesivir decreased upon interaction with the enzyme.