Purification and characterization of dihydropyrimidine dehydrogenase enzyme from sheep liver and determination of the effects of some anaesthetic and antidepressant drugs on the enzyme activity

Dihydropyrimidine dehydrogenase (DPD, E.C. 1.3.1.2) was purified from sheep liver with a yield of 16.7%, purification fold of 407.5 and specific activity of 0.705 EU/mg proteins. The purification procedure consisted of ammonium sulphate fractionation, DEAE ion exchange chromatography and 2',5'-ADP Sepharose-4B affinity chromatography. The molecular weight determined by SDS-PAGE and was found 111 kDa. Optimum pH, ionic strength temperature and stable pH were determined as 8.0, 0.9 mM, 50 degrees C and 6.0, respectively. The kinetic parameters (K-m and V-max) of the enzyme were determined with NADPH as 22.97 mu M and 0.17 EU/mL, respectively. The same parameters were determined with uracil as 17.46 mu M and 0.14 EU/mL, respectively. Additionally, in vitro inhibitory effects of some antidepressant drugs including escitalopram, fluoxetine, mirtazapine, haloperidol and some anaesthetic drugs including propofol and lidocaine were investigated against DPD. In addition, IC50 values for each active drug obtained for escitalopram, fluoxetine, mirtazapine, haloperidol, propofol and lidocaine were determined as 1736.11, 13.24, 86.65, 99.03, 0.21 and 15.07 mu M, respectively

The impact of hydroquinone on acetylcholine esterase and certain human carbonic anhydrase isoenzymes (hCA I, II, IX, and XII).

AbstractCarbonic anhydrases (CAs) are widespread and the most studied members of a great family of metalloenzymes in higher vertebrates including humans. CAs were investigated for their inhibition of all of the catalytically active mammalian isozymes of the Zn2+-containing CA, (CA, EC 4.2.1.1). On the other hand, acetylcholinesterase (AChE. EC 3.1.1.7), a serine protease, is responsible for ACh hydrolysis and plays a fundamental role in impulse transmission by terminating the action of the neurotransmitter ACh at the cholinergic synapses and neuromuscular junction. In the present study, the inhibition effect of the hydroquinone (benzene-1,4-diol) on AChE activity was evaluated and effectively inhibited AChE with Ki of 1.22 nM. Also, hydroquinone strongly inhibited some human cytosolic CA isoenzymes (hCA I and II) and tumour-associated transmembrane isoforms (hCA IX, and XII), with Kis in the range between micromolar (415.81 μM) and nanomolar (706.79 nM). The best inhibition was observed in cytosolic CA II

Synthesis and carbonic anhydrase inhibitory activities of new thienyl-substituted pyrazoline benzenesulfonamides.

A series of new thienyl-substituted pyrazoline benzenesulfonamides were synthesized and their carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activities were tested on the human (h) isoforms hCA I and hCA II. The inhibition constant (Ki) of these sulfonamides were in the range of 232.16-637.70 nM toward the slow cytosolic isozyme hCA I, and in the range of 342.07-455.80 nM toward hCA II. Many of these compounds showed comparable inhibition with the reference sulfonamide acetazolamide, a clinically used drug. As the sulfonamide CA inhibitors (CAIs) show many therapeutic uses, these derivatives represent interesting examples of a novel class of such derivatives

Effects of low molecular weight plasma inhibitors of rainbow trout (Oncorhynchus mykiss) on human erythrocyte carbonic anhydrase-II isozyme activity in vitro and rat erythrocytes in vivo

The effects of low molecular weight plasma inhibitors from rainbow trout (Oncorhynchus mykiss) (RT) were investigated on the carbonic anhydrase enzyme (CA) activities in in vitro human and in in vivo Sprague–Dawley rat erythrocytes. The RT blood was used as extracellular fluid (plasma) source and plasma inhibitors were obtained by dialysis of the plasma. For the in vitro study, human carbonic anhydrase-II (HCA-II) isozyme was obtained by Sepharose 4B-l-tyrosine-sulfanylamide affinity chromatography with an overall purification of about 646-fold. The enzyme (specific activity of 7750 EU/mg protein) was obtained with a yield of 71.1% and SDS-PAGE showed a single band. From in vitro studies, the I50 value for RT plasma inhibitors obtained was 0.37 mg/ml. From in vivo studies on rat erythrocytes, CA activity was significantly inhibited by the inhibitors from the extracellular fluid of RT for up to 3 h (p<0.05) following intraperitoneal administration

Carbonic anhydrase inhibitory properties of novel sulfonamide derivatives of aminoindanes and aminotetralins.

We are greatly indebted to The Scientific and Technological Research Council of Turkey (TUBITAK, Grant no. TBAG-109T241) and Ataturk University (BAP2012/152) for their financial support of this study for (YA, AA, SG)

The effects of some avermectins on bovine carbonic anhydrase enzyme

Avermectins are effective agricultural pesticides and antiparasitic agents that are widely employed in the agricultural, veterinary and medical fields. The aim of this study was to investigate the inhibitory effects of selected avermectins including abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin that are used as drugs against a wide variety of internal and external mammalian parasites, on the carbonic anhydrase enzyme (CA, EC 4.2.1.1.) purified from fresh bovine erythrocyte. CA catalyses the rapid interconversion of carbon dioxide (CO2) and water (H2O) to bicarbonate ([Formula: see text]) and protons (H(+)) and regulate the acidity of the local tissues. Bovine erythrocyte CA (bCA) enzyme was purified by Sepharose-4B affinity chromatography with a yield of 21.96% and 262.7-fold purification. The inhibition results obtained from this study showed Ki values of 9.73, 17.39, 20.43, 13.39, 16.44 and 17.73 nM for abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin, respectively. However, acetazolamide, well-known clinically established CA inhibitor, possessed a Ki value of 27.68 nM

The effect of caffeic acid phenethyl ester (CAPE) on metabolic enzymes including acetylcholinesterase, butyrylcholinesterase, glutathione S-transferase, lactoperoxidase, and carbonic anhydrase isoenzymes I, II, IX, and XII.

This work was financed in part by two EU projects of the 7th FP, Metoxia and Dynano. Also, IG and SE would like to extend his sincere appreciation to the Research Chairs Program at King Saud University for providing funding to this research

Evaluation of Natural Radioactivity and Radiological Hazards in Some Building Materials Used in Kars

Bu çalışmada, Kars ilinde kullanılan bazı yapı malzemelerinin radyoaktivite seviyeleri ve bu malzemelerinin kullanılmasından kaynaklanabilecek radyolojik riskler belirlendi. Kars'ın değişik bölgelerinden 10 farklı yapı malzemesini (kireçtaşı, kil, tras, alçıtaşı, demir cevheri ve dört farklı çimento numunesi) temsil eden toplam 60 numune toplanmıştır. Bu numunelerdeki 226Ra, 232Th ve 40K radyoizotoplarının radyoaktivite konsantrasyonları HPGe gama ışını spektrometre sistemi ile ölçüldü. 226Ra, 232Th ve 40K radyoizotoplarının ortalama radyoaktivite konsantrasyonları sırasıyla 22,87 Bq kg-1 , 19,49 Bq kg-1 , 265,29 Bq kg-1 ve 1,7 Bq kg-1 olarak bulundu. Elde edilen değerler kullanılarak yapı malzemeleri için radyolojik tehlike indisleri (radyum eşdeğer aktivitesi, yapı içi soğurulmuş doz hızı, yapı içi etkin doz hızı, I indisi ve I indisi) hesaplandı. Bu sonuçlar Türkiye’de ve dünyadaki çeşitli ülkelerde benzer malzemeler için bildirilen sonuçlarla kıyaslandı. Bu araştırmanın sonucunda incelenen yapı malzemelerinin radyolojik bir risk oluşturmadığı ve binaların inşasında güvenle kullanılabileceği görülmüştür.In this study, radioactivity levels of some building materials used in Kars province and radiological risks that could arise from these building materials were determined. A total of 60 samples representing 10 different building materials (limestone, clay, tras, gypsum, iron core and four different cement samples) from various regions of Kars were collected. The radioactivity concentrations of 226Ra, 232Th and 40K radioisotopes in these samples were measured using an HPGe gamma-ray spectrometry system. The mean radioactivity concentrations of 226Ra, 232Th and 40K were found to be 22.87 Bq kg-1 , 19.49 Bq kg-1 , 265.29 Bq kg-1 and 1.74 Bq kg-1 , respectively. Radiation hazard indices (radium equivalent activity, absorbed dose rate indoors, annual effective dose rate indoors, I index and I index) were calculated for the building materials using these obtained values. These results were compared with the results reported for similar materials in Turkey and in several countries around the world. As a result of this research, it was observed that the building materials examined did not constitute a radiological risk and could be used safely in the construction of buildings

Synthesis and inhibitory properties of some carbamates on carbonic anhydrase and acetylcholine esterase

A series of carbamate derivatives were synthesized and their carbonic anhydrase I and II isoenzymes and acetylcholinesterase enzyme (AChE) inhibitory effects were investigated. All carbamates were synthesized from the corresponding carboxylic acids via the Curtius reactions of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The carbamates were determined to be very good inhibitors against for AChE and hCA I, and II isoenzymes. AChE inhibition was determined in the range 0.209-0.291 nM. On the other hand, tacrine, which is used in the treatment of Alzheimer's disease possessed lower inhibition effect (Ki: 0.398 nM). Also, hCA I and II isoenzymes were effectively inhibited by the carbamates, with inhibition constants (Ki) in the range of 4.49-5.61 nM for hCA I, and 4.94-7.66 nM for hCA II, respectively. Acetazolamide, which was clinically used carbonic anhydrase (CA) inhibitor demonstrated Ki values of 281.33 nM for hCA I and 9.07 nM for hCA II. The results clearly showed that AChE and both CA isoenzymes were effectively inhibited by carbamates at the low nanomolar levels

Secondary sulfonamides as effective lactoperoxidase inhibitors

Secondary sulfonamides (4a–8h) incorporating acetoxybenzamide, triacetoxybenzamide, hydroxybenzamide, and trihydroxybenzamide and possessing thiazole, pyrimidine, pyridine, isoxazole and thiadiazole groups were synthesized. Lactoperoxidase (LPO, E.C.1.11.1.7), as a natural antibacterial agent, is a peroxidase enzyme secreted from salivary, mammary, and other mucosal glands. In the present study, the in vitro inhibitory effects of some secondary sulfonamide derivatives (4a–8h) were examined against LPO. The obtained results reveal that secondary sulfonamide derivatives (4a–8h) are effective LPO inhibitors. The Ki values of secondary sulfonamide derivatives (4a–8h) were found in the range of 1.096 × 10−3 to 1203.83 µM against LPO. However, the most effective inhibition was found for N-(sulfathiazole)-3,4,5-triacetoxybenzamide (6a), with Ki values of 1.096 × 10−3 ± 0.471 × 10−3 µM as non-competitive inhibition