A novel diisopropylphosphofluoridate-sensitive phenylalanine arylamidase in human liver.
A diisopropylphosphofluoridate-sensitive (DFP-sensitive) arylamidase, which preferentially hydrolyzed Phe-p-nitroanilide (Phe-pNA), was purified from a crude extract of human liver by conventional chromatographic techniques. The purified enzyme gave a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 58,000 by SDS-polyacrylamide gel electrophoresis and 200,000 by chromatography on a column of Sephacryl S-300, suggesting that the enzyme is a trimer or a tetramer. The enzyme was inactivated in proportion to the amount of [3H]DFP incorporated with a [3H]DFP/subunit (58,000) molar ratio of 1.04. The data indicate that the enzyme belongs to the serine protease family.
Narita
Y
Y
Department of Biochemistry, Nagoya City University Medical School, Japan.
Moriyama
A
A
Nakanishi
M
M
Hayakawa
T
T
Katagiri
K
K
Sasaki
M
M
D000596:Amino Acids / Q000032:analysis; D000626:Aminopeptidases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis; D002852:Chromatography, Ion Exchange; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007531:Isoflurophate / Q000494:pharmacology*; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D010649:Phenylalanine / Q000378:metabolism*
D000596:Amino Acids; D002241:Carbohydrates; D007531:Isoflurophate; D010649:Phenylalanine; D000626:Aminopeptidases