title: Partial purification and characterization of PAF acetylhydrolase in human amniotic fluid.
abstract: Platelet-activating factor (PAF) acetylhydrolase, which removes the acetyl moiety at thesn-2 position, has been found in human amniotic fluid. We purified this enzyme by ammonium sulfate precipitation, and sequential use of DEAE-Sepharose CL-6B, hydroxyapatite, chelating-Sepharose, and Mono Q column chromatographies. This enzyme exhibited broad pH optima and was unaffected by EDTA. Partially purified enzyme had a molecular weight of approximately 34 kDa on SDS-PAGE. In addition, the enzyme activity was inhibited by either diisopropylfluorophosphate(DFP) orp-bromophenacylbromide (p-BPB), suggesting that this enzyme possesses active serine and histidine residues. The enzyme showed similar activity towards PAF and oxidatively modified phosphatidylcholine, but didn't hydrolyze phosphatidylcholine or phosphatidylethanolamine with a long chain fatty acyl group atsn-2 position.
authors.affiliation: College of Pharmacy, Yeungnam University, 712-749, Gyongsan, Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Son
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Baek
authors.forename: H W
authors.initials: HW
authors.lastname: Chang