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Öğe Changes in carbonic anhydrase activity and gene expression of Hsp70 in rainbow trout (Oncorhynchus mykiss) muscle after exposure to some metals(2012) Söyüt H.; Beydemir S.; Ceyhun S.B.; Erdo?an O.; Kaya E.D.The effects of some heavy metals Co(II), Cu(II), Zn(II), and Ag(I) on carbonic anhydrase (CA) activity from rainbow trout (RT) muscle were investigated. Moreover, the effects of these metals on the expression of heat shock protein 70 (Hsp70) gene in muscle tissue were examined by real-time quantitative PCR (RT-PCR) in muscle tissue aft er exposure to the metals at the end of 6, 12, 24, and 48 h. CA was purified with a specific activity of 2300 EU mg-1, a yield of 19%, and 1080-fold. The molecular weights (Mw) of subunit and native enzyme were approximately 30 and 31 kDa, respectively. Optimum pH, stable pH, optimum temperature, activation energy (E?), activation enthalpy (?H), and Q10 (the difference in activity of enzyme caused by the increment of 10 oC) value were determined. Apparent Michaelis constant (Km), maximum reaction rate (Vmax), and turnover rate of the enzyme (Kcat) values were 1.29 mM, 0.17 ?mol min-1, and 28.8 s-1, respectively. The catalytic efficiency (Kcat/Km) was 22.3. The heavy metals decreased in vitro CA activity. Inhibition mechanisms of the metal ions were noncompetitive, except for the Co(II) ion, which was competitive. The expression of the Hsp70 gene was increased in the presence of the metal ions. The expression level at the end of 48 h was the highest for all of the metals. Consequently, the in vitro inhibition rank order was determined as Co(II) > Zn(II) > Cu(II) > Ag(I). Interestingly, Ag(I) was the most effective metal ion on Hsp70 gene expression. © TÜBİTAK.Öğe Effect of calcium channel blockers on paraoxonase-1 (PON1) activity and oxidative stress(Elsevier B.V., 2014) Türkeş C.; Söyüt H.; Beydemir S.Background: In this study, we investigated the in vitro effects of calcium channel blockers (nifedipine, nitrendipine, isradipine, and amlodipine besylate) on the activity of paraoxonase-1 (PON1). Methods: PON1 was purified from human serum using simple chromatographic methods, including DEAE-Sephadex anion-exchange and Sephadex G-200 gel filtration chromatography. Results: The calcium channel blockers decreased the in vitro PON1 activity. The inhibition mechanism of amlodipine besylate was noncompetitive, whereas nifedipine, nitrendipine, and isradipine were competitive inhibitors. Conclusions: Our results showed that calcium channel blockers exhibit inhibitory effects on PON1 at low concentrations. The IC50 values for nifedipine, nitrendipine, isradipine, and amlodipine besylate were determined to be 0.121 mM, 0.130 mM, 0.255 mM, and 0.304 mM, respectively, and the Ki constants were calculated to be 0.222 ± 0.049 mM, 0.151 ± 0.067 mM, 0.286 ± 0.137 mM, and 0.321 ± 0.002 mM, respectively. © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.Öğe Impact of antibacterial drugs on human serum paraoxonase-1 (hPON1) activity: An in vitro study(Asian Pacific Tropical Biomedicine Press, 2014) Söyüt H.; Kaya E.D.; Beydemir S.Objective: To investigate the in vitro effects of the antibacterial drugs, meropenem trihydrate, piperacillin sodium, and cefoperazone sodium, on the activity of human serum paraoxonase (hPON1). Methods: hPON1 was purified from human serum using simple chromatographic methods, including DEAE-Sephadex anion exchange and Sephadex G-200 gel filtration chromatography. Results: The three antibacterial drugs decreased in vitro hPON1 activity. Inhibition mechanisms meropenem trihydrate was noncompetitive while piperacillin sodium and cefoperazone sodium were competitive. Conclusions: Our results showed that antibacterial drugs significantly inhibit hPON1 activity, both in vitro, with rank order meropenem trihydrate piperacillin sodium cefoperazone sodium in vitro. © 2014 by the Asian Pacific Journal of Tropical Biomedicine.Öğe The impact of heavy metals on the activity of carbonic anhydrase from rainbow trout (Oncorhynchus mykiss) kidney(2012) Söyüt H.; Beydemir S.Many environmental and health problems have become a consequence of contamination of soil and water by toxic heavy metals and organic pollutants in the present age of technology. Heavy metals play vital roles in enzyme activities and other metabolic events with their bioaccumulative and nonbiodegradable properties among aquatic pollutants. Metal toxicity causes irregular metallothioneins protein synthesis, renal damage, and disruption of bone structure in humans and wildlife. In this study, we investigated in vitro effects of some metals on chemical-targeted carbonic anhydrase (CA) enzyme from rainbow trout kidney. The enzyme was purified with a specific activity of 17,285 EU × mg-1 and 31.7% yield and approximately 1800-fold using simple affinity purification method. Molecular weights of the subunit and native enzyme were estimated as 28.7 kDa and 26.9 kDa via sodium dodecyl sulfate polyacrylamide gel electrophoresis and Sephadex-G 200 column, respectively. Other kinetic properties of the enzyme were determined. Apparent Km, Vmax and kcat values were 0.40 mM, 0.097 ?mol min-1 and 15.2 s-1 for p-nitrophenylacetate substrate, respectively. Inhibitory effects of cobalt, zinc, copper, cadmium and silver on CA activity were determined using the esterase method under in vitro conditions. IC50 and Ki values were calculated for metals. Ki values for Co2+, Zn2+, Cu2+, Cd2+ and Ag+ were 0.035, 1.2, 34.8, 103 and 257 from Lineweaver-Burk graphs, respectively. Consequently, in vitro inhibition rank order was determined as Co2+ > Zn2+ > Cu 2+ > Cd2+ > Ag+. The potential inhibitor for CA was found as Co2+ from these results. © 2011 The Author(s).Öğe In vitro inhibitory effects of palonosetron hydrochloride, bevacizumab and cyclophosphamide on purified paraoxonase-I (hPON1) from human serum(Elsevier B.V., 2016) Türkeş C.; Söyüt H.; Beydemir S.In this study, we investigated the effects of the drugs, palonosetron hydrochloride, bevacizumab and cyclophosphamide, on human serum paraoxonase-I (hPON1) enzyme activity in in vitro conditions. The enzyme was purified ~231-fold with 34.2% yield by using ammonium sulphate precipitation, DEAE-Sephadex A-50 ion-exchange chromatography and Sephadex G-200 gel-filtration chromatography from human serum. hPON1 exhibited a single protein band on the SDS polyacrylamide gel electrophoresis. The inhibition studies were performed on paraoxonase activity of palonosetron hydrochloride, bevacizumab and cyclophosphamide. Ki constants were found as 0.033 ± 0.001, 0.054 ± 0.003 mM and 3.419 ± 0.518 mM, respectively. Compared to the inhibition rates of the drugs, palonosetron hydrochloride has the maximum inhibition rate. However, inhibition mechanisms of the drugs were determined as noncompetitive by Lineweaver-Burk curves. © 2016 Elsevier B.V.Öğe Mechanism of capsaicin inhibition of aldose reductase activity(John Wiley and Sons Inc., 2017) Alim Z.; Kilinc N.; Sengul B.; Beydemir S.Aldose reductase (AR) inhibitors play a vital importance as a potential therapeutic and preventive medicine when it comes to hyperglycemia associated diabetic complications. Additionally, capsaicin is used as a food additive and a drug in a number of diverse clinical trials. The aim of this study is to determine the in vitro inhibition behavior of capsaicin on AR enzyme activity, which was obtained from different rat tissues (heart, kidney, liver, and brain). We showed that AR was inhibited by capsaicin in the micromolar range and noncompetitive manner in all of the tissues. Ki values of capsaicin were found to be 8.87, 264, 535, and 597, respectively, in heart AR, kidney AR, liver AR, and brain AR. In conclusion, capsaicin may be an effective molecule when used in low concentrations to prevent diabetic complications associated with the polyol pathway. © 2017 Wiley Periodicals, Inc.Öğe Synthesis and carbonic anhydrase inhibitory properties of novel bromophenols including natural products(2012) Balaydiin H.T.; Soyut H.; Ekinci D.; Göksu S.; Beydemir S.; Menzek A.; Şahin E.(2-Bromo-3,4-dimethoxyphenyl) (3,4-dimethoxyphenyl)methanone (10) and its derivatives with Br, one dibromide and isomeric three tribromides, were synthesized. Demethylation of these compounds afforded a series of new bromophenols. Inhibition of human cytosolic carbonic anhydrase II (hCA II) isozyme by these new bromophenols and naturally occurring 3,4,6-tribromo-5-(2,5- dibromo-3,4-dihydroxybenzyl)benzene-1,2-diol (3), and 5,5?-methylenebis(3, 4,6-tribromo-benzene-1,2-diol) (4) was investigated. The synthesized compounds showed carbonic anhydrase inhibitory capacities with IC 50 values in the range of 0.7372 ?M against hCA II. Some bromophenols investigated here showed effective hCA II inhibitory activity and might be used as leads for generating novel carbonic anhydrase inhibitors which are valuable drug candidates for the treatment of glaucoma, epilepsy, gastric and duodenal ulcers, neurological disorders, or osteoporosis. © 2012 Informa UK, Ltd.
