Characterization of Carboxylesterases in Rat and Guinea Pig: Their Heterogeneityand Role in Detoxication of Organophosphorus Compounds

摘要

The present study deals with the molecular properties of carboxylesterases(CarbEs) and the ability of the various isoenzymes to detoxify organophosphorus compounds. CarbE isoenzymes have been separated from lung, liver, plasma and small intestine of rat and guinea pig mainly by chromatofocusing. Monoclonal antibodies (MAbs) were prepared against the purified isoenzyme and used in enzyme-linked immunosorbent assays (ELISA) to distinguish between the CarbE isoenzymes in the different tissues. The molecular and immunological results showed a strong relationship between lung CarbE, pI 5.8, and the rat liver CarbE, pI 6.0. The MAbs were strongly bound to the high pI forms of the CarbE isoenzymes in plasma and small intestine from rat and guinea pig, but not to the low pI forms. This indicates that at least two immunochemically distinct categories of isoenzymes are present in both plasma and intestine.