Yazar "Demir N." seçeneğine göre listele

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    Expression of cytosolic and noncytosolic carbonic anhydrase enzymes from bovine brain membrane
    (2012) Demir N.; Demir Y.; Coskun F.; Tasgin E.
    Carbonic anhydrase is an enzyme that takes responsibility in inhalation function but, until today, carbonic anhydrase is not examined if it is present in the bovine brain membrane or not. The enzyme carbonic anhydrase was purified and separately characterized according to the bonding forms in 4 steps such as outer peripheral, cytosolic, inner peripheral and integral. Affinity chromatography was used for purification of the enzyme in all four steps. The affinity column was prepared with sepharose-4B-L-tyrosine-sulphanilamide. Purified carbonic anhydrase was obtained at each step. Enzyme activity was measured by CO 2 hydratase activity and esterase activity methods. Optimum pH and optimum temperature were defined for purified enzymes at each step. Morover molecular weight and purity were detected by gel filtration and SDS-PAGE electrophorose. In addition, the enzyme's Km and n max values were found with the Lineweaver- Burk method. The obtained results are discussed in comparison with other mammalian carbonic anhydrases. Carbonic anhydrase was shown to be exist in bovine brain membrane and this enzyme was optimized.
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    Production of a novel pectin lyase from Bacillus pumilus (P9), Purification and characterisation and fruit juice application
    (2010) Nadaro?lu H.; Taşkin E.; Adigüzel A.; Güllüce M.; Demir N.
    Extracellular pectin lyase (EC 4.2.2.10) was produced by Bacillus pumilus (P9) in solid state fermentation. Pectin lyase enzyme was purified 36.36 fold by using DEAE-cellulose anion exchange column chromatography and characterized. Molecular weight of the enzyme was determined as 25 kDa by using Sephadex G-100 gel filtration chromatography. Purification of enzyme was controlled by SDS-PAGE. The optimum pH and temperature of enzyme was determined as pH 6.0 and 60oC, respectively. Pectin lyase was mostly stable at 40°C. Its' activity deceased in 50% for 1h at 60°C and 40% for 4 h at 50°C. Vmax and KM were calculated respectively as 0.298 mg/mL and 132.6 mol/L*min. The presence of 10 mM concentration of Ca2+, Cu2+, Mn2+, Mg2+, Zn2+, Hg2+, Fe2+ and EDTA, L-cystein, ascorbic acid and -mercaptoethanol significantly enhanced the pectin lyase of the purified enzyme. The purified pectin lyase enzyme was used for getting fruits juices. It was determined that yields of fruits juices significantly improved when it was compared with control. © 2010 University of Bucharest.
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    Production of pectin lyase from xanthomonas campestris, purification, characterization and fruit juice application
    (EM International, 2014) Celik S.Y.; Demir Y.; Demir N.; Güllüce M.
    Extracellular pectin lyase (EC 4.2.2.10) was produced by Xanthomonas campestris in solid state fermentation. Solid state fermentation was carried out using 250 mL Erlenmeyer flasks containing 5 g wheat bran, 1% citrus pectin and 10 mL salt mixture that composed of 0.14% (NH4)2SO4 0.02% MgCl2 and 0.02% K2HPO4. Pectin lyase enzyme was purified 43 fold by using DEAE-cellulose anion exchange column chromatography and characterized. Molecular weight of the enzyme was determined as 77.5 kDa by using Sephadex G-100 gel filtration chromatography. Purification of enzyme was controlled by SDS-PAGE. The optimum pH and temperature of enzyme was determined as pH 9.0 and 50°C, respectively. Pectin lyase was mostly stable 40°C for 24 hours. KM and Vmax were calculated respectively as 0.69 mg/mL and 3.84 |?mol/L?min. Purified pectin lyase was inhibited by Fe+, Zn2+, Ca2+, Co2+ and Hg2+ except for Cu2+ and Mg2+ The purified pectin lyase enzyme was used for getting fruits juices. It was determined that yields of fruits juices improved when it was compared with control.
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    Purification and characterization of a pectin lyase produced by Geobacillus stearothermophilus Ah22 and its application in fruit juice production
    (2011) Demir N.; Nadaroglu H.; Tasgin E.; Adiguzel A.; Gulluce M.
    Extracellular pectin lyase (PL) (EC 4.2.2.10) was produced by Geobacillus stearothermophilus Ah22 in solid state fermentation. The PL enzyme was purified 40.8-fold by DEAE-cellulose anion exchange column chromatography and characterized. The molecular weight of the enzyme was determined as 36 kDa by Sephadex G-100 gel filtration chromatography. Purification of the enzymewas verified by SDS-PAGE. The optimumpHand temperature of the enzyme were determined as pH 6.0 and 60°C, respectively. The PL was mostly stable at 40°C. Its activity deceased by 50% after 2 h at 60°C and by 60% after 6 h at 50°C. The V max and K m were calculated as 0.47 mg/mL and 355.3 ?mol/L•min, respectively. The presence of 10 mM Ca 2+, Cu 2+, Mn 2+, Mg 2+, Zn 2+, Hg 2+, Fe 2+ and EDTA, L-cysteine and ascorbic acid significantly enhanced enzyme activity. The purified PL enzyme was used in the production of fruit juices; yields of fruits juice improved significantly compared with controls. © 2011 Springer-Verlag and the University of Milan.
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    Purification and characterization of an alkaline pectin lyase produced by a newly isolated brevibacillus borstelensis (p35) and its applications in fruit juice and oil extraction
    (Springer Verlag, 2014) Demir N.; Nadaroglu H.; Demir Y.; Isik C.; Taskin E.; Adiguzel A.; Gulluce M.
    An alkaline pectin lyase (Pnl) (EC 4.2.2.10) secreted by Brevibacillus borstelensis P35 (genBank number: FJ417406) was purifed using ammonium sulfate fractionation, anion exchange chromatography on DEaE-cellulose and gel fltration chromatography on Sephadex g-150. The pH and temperature optima of the enzyme were found to be 8.0 and 60 °C. The enzyme does not loose activity up to 60 °C if exposed for 1 h. The values of Kmand Vmax of the enzyme were 0.625 mg/ml and 126.32 s-1, respectively. The molecular weight was found to be 36 ± 01 kDa. The presence of 10 mM concentration of Ca2+, Cu2+, Mn2+, Mg2+, Zn2+, Hg2+, Fe2+ and EDTa, L-cystein, ascorbic acid signifcantly enhanced the Pnl of the purifed enzyme. In the course of the laboratory trials, it was demonstrated that Pnl from B. borstelensis (P35) could be successfully applied to the production and clarif-cation of fruit juice and oil extraction. © Springer-Verlag Berlin Heidelberg 2014
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    Purification and properties of carbonic anhydrase from bone marrow
    (2009) Tasgin E.; Nadaroglu H.; Demir Y.; Demir N.
    In this work, the carbonic anhydrase was purified from bovine bone marrow and investigated its kinetic properties. Carbonic anhydrase was purified from bovine bone marrow using affinity chromatography by sepharose 4B-L-tyrosine sulphanilamide. During purification steps, the activity of enzyme was measured using p-nitrophenyl acetate at pH: 7.4. Optimum pH and optimum temperature values for bovine bone marrow carbonic anhydrase were determined and then K m and Vmax values for the same substrate were obtained by means of Linewearver-Burk graphics. The purification degree for bovine bone marrow was calculated. The Vmax, and Km values at optimum pH and at 20 °C for the substrate (p-nitrophenyl acetate) were 120.418 u?mol/L min and 2.409 x 103 mM, respectively. The K1 and I50 values for sulfanilamide, KSCN, NaN3 and acetazolamide were determined in bovine bone marrow carbonic anhydrase.
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    Purification of paraoxonase enzyme from the sera of patients with behcet’s disease and analyzing the effects of the drugs containing imuran (azathioprine), prednisolone (methylprednisolone) and colchium (colchicine)
    (Bentham Science Publishers B.V., 2014) Demir N.; Nadaroglu H.; Ozkan A.; Tasgin E.; Isik C.; Demir Y.
    In this study, serum samples from 50 patients with the diagnosis of Behcet’s disease and 20 healthy volunteers were analyzed. The study consists of three parts. In the first part, paraoxonase (PON) activities were determined in the serum samples of 50 patients with Behcet’s disease and 20 healthy people. In the second part, equal volumes of serum samples from 50 patients were pooled and PON enzymes were purified by using Sepharose-4B-L-tyrosine tyrosine-1-naphtylamine affinity column. Optimum temperature, optimum pH, Vmax and Km values of the pure enzymes were determined. The same purification procedure was also performed in the serum samples of 20 healthy people. Electrophoretic mobility was observed (via SDS-PAGE) in the PON enzymes that were purified from the serum samples of patients with Behcet’s disease and healthy people. In the third part, in vitro effects of drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of Behcet’s disease were tested on the PON enzymes of the patients with Behcet’s disease and control group. IC50 values and Ki constant values were measured and inhibition types were determined for the drugs containing azathioprine, methylprednisolone and colchicine that have already been used for the treatment of the Behcet’s disease and demonstrate in vitro inhibition effects. ©2014 Bentham Science Publishers.