Purification, characterization, and investigation of in vitro inhibition by metals of paraoxonase from different sheep breeds.

Paraoxonase (PON) was purified and characterized from the Merino and Kivircik sheep's blood serums by a two-step procedure using ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-napthylamine hydrophobic interaction chromatography for the first time. On SDS-polyacyrilamide gel electrophoresis, purified human serum paraoxonase yielded a single band of 66 kDa on SDS-PAGE. The KM and Vmax were 0.482 mM and 41.348 U/mL.dak for Merino PON enzyme, 0.153 mM and 70.289 U/mL.dak for Kivircik PON, respectively. The effect of Mn(2+) , Hg(2+) , Co(2+) , Cd(2+) , Ni(2+) and Cu(2+) heavy metals on purified Merino and Kivircik serum PON in vitro was determined.