A Characterization of Carboxylesterases in Rat and Guinea Pig - Their Heterogeneity and Role in Detoxication of Organophosphorus Compounds
NORWEGIAN DEFENCE RESEARCH ESTABLISHMENT OSLO
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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. One of the isoenzymes in rat lung, pl 5.8, has been purified to near homogeneity. This isoenzymes has a molecular mass of approx 180 kDa with subunits of 60 kDa, and by Edman degradation the first 19 amino acid residues were determined. 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, pl 5.8, and the rat liver CarbE, pl 6.0. The MAbs were strongly bound to the high pl forms of the CarbE isoenzymes in plasma and small intestine from rat and guinea pig, but not to the low pl forms. This indicates that at least two immunochemically distinct categories are present in both plasma and intestine.
- Medicine and Medical Research