title: The inhibitory effect of propofol on bovine lactoperoxidase.
abstract: Propofol (2,6-diisopropylphenol) is a hypnotic intravenous agent with in vivo antioxidant properties. This study was undertaken to examine the in vitro effect of propofol on lactoperoxidase (LPO; E.C. 1.11.1.7) obtained from bovine milk. Lactoperoxidase was purified with three purification steps: Amberlite CG-50 resin, CM-Sephadex C-50 ion-exchange chromatography and Sephadex G-100 gel filtration chromatography, respectively. Lactoperoxidase was purified with a yield of 21.6%, a specific activity of 34 EU/mg proteins and 14.7-fold purification. One enzyme unit is defined as the oxidation of 1 micromol ABTS per min under the assay condition (25( degrees )C, pH: 6.0). To determine enzyme purity, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed and single band was observed. The effect of propofol on lactoperoxidase were determined using 2,2'-azino-bis (3-ethylbenzthiazoline-6 sulfonic acid) diammonium salt (ABTS) as a chromogenic substrate. The IC(50) value of propofol was found as 15.97 microM. Also, K(i) constant for propofol was 3.72 microM and propofol was found as competitive inhibitor.
authors.affiliation: Atatürk University, Science and Arts Faculty, Department of Chemistry, 25240-Erzurum, TR-Turkey.
authors.forename: Melda
authors.initials: M
authors.lastname: Sişecioğlu
authors.forename: Murat
authors.initials: M
authors.lastname: Cankaya
authors.forename: Ilhami
authors.initials: I
authors.lastname: Gülçin
authors.forename: Hasan
authors.initials: H
authors.lastname: Ozdemir
mesh_terms: D000777:Anesthetics / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D020128:Inhibitory Concentration 50; D007700:Kinetics; D007784:Lactoperoxidase / Q000037:antagonists & inhibitors*; D015742:Propofol / Q000494:pharmacology*
chemical_list: D000777:Anesthetics; D007784:Lactoperoxidase; D015742:Propofol