Abstract
Prolyl-beta-naphthylamidase from porcine liver is compared with the two prevalent isoenzymes of pig liver carboxylesterase by isoelectrofocusing experiments and by inhibition studies with phenyl-methyl-sulfonyl fluoride. The results suggest that prolyl-beta-naphthylamidase is identical with the amide-cleaving isoenzyme of carboxylesterase, not with the usually predominant methyl butyrate-hydrolysing isoenzyme. It is questionable whether the recently published sequence of prolyl-beta-naphthylamidase does belong to this enzyme or to the predominant carboxylesterase without amidase activity. Surprisingly, the amide-cleaving carboxylesterase isoenzymes from rat liver have almost no activity with prolyl-beta-naphthylamide.
MeSH terms
-
2-Naphthylamine / analogs & derivatives
-
2-Naphthylamine / metabolism
-
Amino Acid Sequence
-
Aminopeptidases / chemistry
-
Aminopeptidases / isolation & purification
-
Aminopeptidases / metabolism*
-
Animals
-
Carboxylesterase
-
Carboxylic Ester Hydrolases / chemistry
-
Carboxylic Ester Hydrolases / isolation & purification
-
Carboxylic Ester Hydrolases / metabolism*
-
Hydrolysis
-
Isoelectric Point
-
Isoenzymes / chemistry
-
Isoenzymes / isolation & purification
-
Isoenzymes / metabolism
-
Liver / enzymology*
-
Molecular Sequence Data
-
Phenylmethylsulfonyl Fluoride / chemistry
-
Proline / analogs & derivatives
-
Proline / metabolism
-
Rats
-
Swine
Substances
-
Isoenzymes
-
prolyl-beta-naphthylamide
-
Phenylmethylsulfonyl Fluoride
-
Proline
-
2-Naphthylamine
-
Carboxylic Ester Hydrolases
-
Carboxylesterase
-
Aminopeptidases