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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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    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.