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    Comparison of serum paraoxonase 1 (PON1) activities among different sheep breeds in Turkey
    (2011) Arslan, Mikail; Erzengin, Mahmut; Demir, Dudu
    Paraoxonase 1 (PON1, EC 3.1.8.1) is a calcium dependent mammalian enzyme that is synthesized primarily in the liver and is secreted into the serum where it is associated with High Density Lipoproteins (HDLs) and has a protective effect against oxidation of Low Density Lipoproteins (HDLs). Beside antioxidant and antiatherogenic properties, PON1 is also a detoxifier that can hydrolyze toxic organophosphates. Several studies have shown that PON1 can bind reversibly to organophosphate substrates which it hydrolyzes. Therefore, PON1 is the main means of protection of the nervous system against the neurotoxicity of organophosphates entering the circulation. This study was conducted to characterization of serum Paraoxonase 1 (PON1) activity from different sheep breeds namely Karacabey Merino, Kivircik, Tahirova, Akkaraman and Daglic. KM and Vmax values of five different sheep breed were determined by Lineweaver-Burk method. The values of Vmax/KM showed that Kivircik breed has the greatest PON1 activity, on the other hand, Karacabey Merino breed showed the least activity toward paraoxon substrate. © Medwell Journals, 2011.
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    Öğe
    In vitro effects of some antibıotics on enzyme activity of carbonic anhydrase from bovine erythrocytes
    (Parlar Scientific Publications, 2011) Arslan, Mikail; Beyaztaş, Serap; Erzengin, Mahmut
    The purpose of this study was to investigate the in vitro effects of six commonly used veterinary medical drugs (Killoxacin (TM), Gentavet (TM), Geosol (TM), Primoxal (TM), Lypectin (TM) and Penoksal-la (TM)) on erythrocyte bovine carbonic anhydrase (CA, EC 4.2.1.1) activity. The enzyme was purified by affinity chromatography, and the purity was confirmed by SDS-PAGE. Inhibition or activation effects of six different antibiotics on the purified enzyme were determined using the CO2-hydratase activity method. IC50 values of the drugs that caused inhibition were determined by means of Activity % vs [Inhibitor] diagrams. The concentrations of Killoxacin (TM), Gentavet (TM), Geosol (TM), Primoxal (TM) and Lypectin (TM) that inhibited 50% of the enzymatic activity were 9.25, 3.79, 0.72, 6.59 and 2.12 mM, respectively. On the other hand, the enzyme activity was increased by Penoksal-la (TM).
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    Purification and characterization of paraoxonase 1 (PON1) from swiss black, holstein, and montofon bovines
    (Humana Press, 2014) Erzengin, Mahmut; Demir, Dudu; Arslan, Mikail; Sinan, Selma
    Paraoxonase 1 (PON1: EC 3.1.8.1) is a calcium-dependent enzyme associated with high-density lipoproteins (HDLs) and has a protective effect against oxidation of low-density lipoproteins (LDLs) in mammals. PON1 is the best-studied member of a family of enzymes called serum paraoxonases, or PONs, identified in mammals and other vertebrates as well as in invertebrates. PONs exhibit a range of important activities, including drug metabolism and detoxification of organophosphates such as nerve agents. This study reports, for the first time, purification and biochemical characterization of serum PON1 from different bovine breeds namely Swiss Black, Holstein, and Montofon. Bovine serum PON1s were purified using ammonium sulfate precipitation followed by Sepharose-4B-l-tyrosine-1-naphthylamine hydrophobic interaction chromatography. SDS-polyacrylamide gel electrophoresis of the purified enzymes indicates a single band with an apparent MW of 43 kDa. The purified enzymes had a specific activity of 10.78, 27.00, and 22.38 U/mg for Swiss Black, Holstein, and Montofon bovines, respectively. The overall purification rates of our method were 262.47-, 2,476.90-, and 538.06-fold for Swiss Black, Holstein, and Montofon bovines, respectively. Furthermore, using phenyl acetate as a substrate, we determined the K (M) and V (max) values of the purified enzymes, as 0.80 mM, 1428.5 U/ml for Swiss Black; 0.40 mM, 714.3 U/ml for Holstein; and 0.50 mM, 1,111.1 U/ml for Montofon bovine. The present study has revealed that there is no substantial difference in PON1 activities among the studied bovine breeds.
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    Purification of holstein bull semen paraoxonase 1 (pon1) by hydrophobic interaction chromatography and ınvestigation of ıts ınhibition kinetics by heavy metals
    (Humana Press, 2014) Dedeoğlu, Nurcan; Arslan, Mikail; Erzengin, Mahmut
    In this study, paraoxonase 1 (PON1; EC 3.1.8.1) was purified from bull semen, and some characteristics of the enzyme were investigated. In vitro inhibition effect of some heavy metals, including Cu2+, Mn2+, Cd2+, Zn2+, Ni2+, and Pb2+, on the activity of the purified enzyme was also investigated. The purification of bull semen PON1 procedure was composed of two steps: ammonium sulfate precipitation and Sepharose-4B-l-tyrosine-1-naphthylamine hydrophobic interaction chromatography. The enzyme, having a specific activity of 288 EU/mg proteins, was purified 22.67-fold with a yield of 89 %. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of the purified enzyme showed the presence of a single band with an apparent MW of 66 kDa. The V (max) and K (M) values for the paraoxon substrate were determined as 100 EU and 8.0 x 10(-5) M, respectively. The inhibitory effects of different heavy metals on PON1 activity were determined by using the paraoxon as a substrate. The results showed that all the metals, except for Cd2+, inhibited the PON1 enzyme activity in a concentration-dependent fashion. IC50 values of Cu2+, Mn2+, Zn2+, Ni2+, and Pb2+ were found as 2.59 x 10(-3), 1.17 x 10(-3), 42.74 x 10(-3), 99.10 x 10(-3), 48.80 x 10(-3) mM, respectively. Conversely, Cd2+ increased the bull semen PON1 enzyme activity. The present study has demonstrated that Cu2+, Mn2+, Zn2+, Ni2+, and Pb2+ are serious toxic metals, which are able to increase the risk of oxidative stress development and a subsequent decrease of semen quality.