Pruifiying enzym paraoxonase and investigating its kinetic against ghrelin hormone

In this study, enzyme paraoxonase I (E.C. 3.1.1.2. and E.C. 3.1.8.1.) that has major importance for metabolism is tried to be purified from bovine liver. For this purpose homogenization, ultracentrifugation, fractionation with ammonium sulphate precipitation, DEAE-Sepharose ion exchanger chromatography and Sephadex G-200 gel filtration chromatography was applied respectively. In the end of this process Paraoxonase 1 enzyme 23,93 U/mg protein specific activity has been 26,30 fold purified than the homogenate. Molecule weight of Paraoxonase 1 enzyme is measured as 45.2 kDa by SDS-PAGE. Optimum activity of Paraoxonase 1 enzyme has been observed at pH:7.1 and 37 0C. Phenyl acetate used as substrat, Km value was 0,074 + 0,002 mM and Vmax value was 36,42 U/mg. It is observed Paraoxonase 1 enzyme effects to ghrelin hormone and turns 61.20% of active ghrelin hormone to inactive ghrelin hormone in after 20 minutes.Key Words: Paraoxonase I, purification, bovine liver, ghrelin, HPLC