Üreaz içeren immobilize enzim komplekslerinin hazırlanması ve kullanım olanaklarının araştırılması

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.vn ABSTRACT PREPARATION AND APPLICATION POSSIBILITIES OF ENZYME COMPLEXES CONTAINING UREASE HAMARAT BAYSAL, Şenay PhD Thesis, Biochemistry Department Supervisor: Prof. Dr. Arif H. USLAN Ekim, 2000,187 page No intravenously enjectable preparate containing Urease as an alternative to hemodialysis, hemoperrusion and CAPD systems in patients having chronic renal failure has been encountered in literature. In this study, it has been aimed to convert blood urea to alanine by using Urease/AlaDH and PEG-Urease/PEG-AlaDH enzyme pairs within erythrocytes. The production of pyruvate and NADH by erythrocyte required in the second stage of the reaction will make the process a feasible and ceaseless one. The success of the system will enable the renal patients to curve themselves as the patients with diabetes mellitus. Urease/AlaDH were covalently immobilized on activated PEG and optimum conditions of PEG-Urease/PEG-AlaDH enzyme system obtained by preparative and kinetic studies. Urease was encapsulated erythrocyte by using slow dialysis methods and optimum conditions of encapsulation were obtained. Urease, AlaDH, PEG-Urease and PEG- AlaDH were encapsulated within erythrocyte and encapsulation yield, hemoglobine release and the change of erythrocyte shape were determined for each sample. Therefore, the fact of enzyme concentration on encapsulation were investigated. Urease/AlaDH and PEG- Urease/PEG-AlaDH enzyme pairs were encapsulated within erythrocyte at optimal conditional and the ability of alanine synthesis in this systems were determined. Keywords: Urease, AlaDH, erythrocyte, encapsulation, encapsulation in erythrocyte, artificial cell, uremia.ÖZET ÜREAZ İÇEREN ÎMMOBÎLÎZE ENZİM KOMPLEKSLERİNİN HAZIRLANMASI VE KULLANIM OLANAKLARININ ARAŞTIRILMASI HAMARAT BAYSAL, Şenay Doktora Tezi, Biyokimya Bölümü Tez Yöneticisi: Prof. Dr. Arif H. USLAN Ekim, 2000,187 sayfa Kronik böbrek yetmezliği hastalarında hemoliz, hemoperfüzyon ve CAPD sistemlerine alternatif olarak doğrudan kana enjekte edilebilecek üreaz içeren bir enzim preparatına literatürde rastlanmamıştır. Bu çalışmada, canlı eritrositlerde Üreaz/AlaDH ve PEG-Üreaz/PEG-AlaDH enzim çiftleri ile kan üresinin alanine dönüştürülmesi planlanmıştır.Reaksiyonun ikinci kısmı için gerekli piruvat ve NADH' m eritrositlerin doğal metabolizmaları sonucu üretiliyor olması sisteme ekonomiklik ve süreklilik kazandıracaktır. Sistemin başarısı böbrek hastalarını şeker hastalan gibi kendi kendilerini tedavi eder hale getirecektir. Üreaz ve AlaDH enzimleri aktif PEG ile immobilize edilerek PEG- Üreaz/PEG-AlaDH enzim sisteminin çalışma koşulları optirnizasyonu preparatif ve kinetik çalışmaları ile sağlanmıştır. Eritrositlerde enkapsülasyonda yavaş diyaliz yöntemi kullanılmış ve Üreaz enziminin enkapsülasyonu ile sistemin optirnizasyonu sağlanmıştır. Belirlenilen optimum koşullarda Üreaz, AlaDH, PEG-Üreaz ve PEG-AlaDH enzim türevleri eritrositlerde enkapsüle edilerek enkapsülasyon verimi, hemoglobin salınımı ve eritrosit şekillerindeki değişim izlenerek her bir enzim derişinıinin enkapsülasyon üzerine etkileri belirlenmiştir. Belirli oranlarda Üreaz/AlaDH ve PEG-Üreaz/PEG-AlaDH enzim çiftleri eritrositlerde enkapsüle edilerek sistemlerin alanin sentez yetenekleri saptanmıştır

Immobilization of urease using glycidyl methacrylate grafted nylon-6-membranes

WOS: 000245021300020The graft copolymerization of glycidyl methacrylate (GMA) onto nylon-6-membrane using benzophenone (BP) as an initiator was carried out in an alcoholic aqueous solution. The acrylic double bond of GMA participated in the grafting onto the nylon-6-membrane backbone with the epoxy groups remaining unaffected. At the end of the grafting reaction, urease was immobilized onto the modified membrane. BP concentration, GMA concentration and organic solvent seperation were studied by determining the grafting percentage. The influence of urease concentration on the immobilization efficiency was also studied. With keeping other conditions constant, the optimum conditions were shown as following [BP]: 5 x 10(-2) mM; [GMA]: 10 M; [urease]: 10 mg/ml, organic solvent: methanol. (c) 2006 Published by Elsevier Ltd

Biosorption of Chromium, Cadmium, and Cobalt from Aqueous Solution by Immobilized Living Cells of Chryseomonas luteola TEM 05

WOS: 000269668300007PubMed ID: 19739028In this work, the potential use of the immobilized cells of Chryseomonas luteola TEM 05 for the removal of Cr+6, Cd+2 and Co+2 ions from aqueous solutions was investigated. The living cells of C. luteola TEM 05 were firstly entrapped both in carrageenan and chitosan coated carrageenan gels and then used in biosoption of the metal ions in batch reactors at pH 6.0, 25 degrees C, in 100mg L-1 of each metal solution. Besides this, a process of competitive biosorption of these metal ions was also described and compared to single metal ion adsorption in solution. According to the immobilization results, the replacement of KCl by KCl-chitosan as gelling agent improved the mechanical strength and thermal stability of the gel. In addition, the C. luteola TEM 05 immobilized carrageenan-chitosan gel system was quite more efficient for the fast adsorption of metal ions from aqueous solution than the carrageenan gels without biomass.Ege University Research FundEge University [FEN 005]This work was supported by Ege University Research Fund Project 2004 FEN 005

Investigation of metal activation of a partially purified polyphenol oxidase enzyme electrode

7th Workshop on Biosensors and BioAnalytical Mu-Techniques for Environmental and Clinical Analysis -- SEP 10-14, 2006 -- Kusadasi, TURKEYWOS: 000248051600008Biosensors can be developed using different biological materials and immobilization technologies. Enzymes are generally used in biosensor construction, and some enzymes need metal ions or small organic molecules as a cofactor for their activation. Polyphenol oxidases can be activated by several metal ions such as Cu2+, Mg2+, Zn2+, Mn2+, and Ni2+. In this study, a new measurement method has been developed that is based on the metal ion activation of the polyphenol oxidase enzyme used in the biosensor preparation, especially to determine the concentration of Mg2+ ions. Polyphenol oxidase (PPO) (EC 1.10.3.1) was partially purified from potato (Solanum tuberosum) by using (NH4)(2)SO4 precipitation, dialysis, and lyophylization processes. As a result of this processes, approximately 30-fold purification was achieved for PPO. For construction of the biosensor, the enzyme was immobilized on the dissolved oxygen probe membrane using gelatin and glutaraldehyde (2.5%). Using the biosensor, we obtained responses for catechol in the absence and presence of Mg2+ ions. Differences between the biosensor responses were related to the concentration of Mg2+ ions. The biosensor response depends linearly on concentration of Mg2+ ions between 0.05 and 7.5mM. In the optimization studies, phosphate buffer (pH 7.0, 50mM) and 35 degrees C were determined to be the optimum conditions. This project will be a novel biosensor study and it might bring a new term, 'activation based biosensor' into the biosensor area

Studies on the applicability of alginate-entrapped Chryseomonas luteola TEM 05 for heavy metal biosorption

WOS: 000248159700054PubMed ID: 17412497Chryseomonas luteola TEM 05 cells were entrapped both in alginate and chitosan coated alginate beads. Biosorption of metal ions on alginate beads was investigated by using a batch stirred system at pH 6.0, 25 degrees C, in initial metal concentration of 1.92 mM of Cr6+ 0.89 MM Cd2+ and 1.69 mM Co2+. Then, a process of competitive biosorption of these metal ions was described and compared to single metal ion adsorption in solution. The apparent equilibrium biosorption was reached within the 180 min of contact for all metals. Although the competitive biosorption capacities of the beads for all metal ions were lower than those of single conditions, Cd2+ biosorption on alginate and alginate-chitosan beads did not change significantly. (C) 2007 Elsevier B.V. All rights reserved

Comparative studies on the adsorption of Cr(VI) ions on to various sorbents

WOS: 000241710400026PubMed ID: 16580196The adsorption of Cr(VI) ions onto various sorbents (chitin, chitosan, ion exchangers; Purolite CT-275 (Purolite 1), Purolite MN-500 (Purolite 11) and Amberlite XAD-7) was investigated. Batch adsorption experiments were carried out as a function of pH, agitation period and concentration of Cr(VI) ions. The optimum pH for Cr(VI) adsorption was found as 3.0 for chitin and chitosan. The Cr(VI) uptake by ion exchangers was not very sensitive to changes in the pH of the adsorption medium. The maximum chromium sorption occurred at approximately 50 min for chitin, 40 min for Purolite 11 and 30 min for chitosan, Purolite I and Amberlite XAD-7. The suitability of the Freundlich and Langmuir adsorption models were also investigated for each chromium-sorbent system. Adsorption isothermal data could be accurately interpreted by the Langmuir equation for chitosan, chitin, Purolite I and Purolite 11 and by the Freundlich equation for chitosan, chitin and Amberlite XAD-7. The chromium(VI) ions could be removed from the sorbents rapidly by treatment with an aqueous EDTA solution and at the same time the sorbent regenerated and also could be used again to adsorb by heavy metal ions. The results showed that, chitosan, which is a readily available, economic sorbent, was found suitable for removing chromium from aqueous solution. (c) 2006 Published by Elsevier Ltd

Encapsulation of PEG-Urease/PEG-AlaDH within sheep erythrocytes and determination of the system's activity in lowering blood levels of urea in animal models

WOS: 000248721800005PubMed ID: 17701485Urease and AlaDH enzymes immobilized on active PEG derivatives were encapsulated at different ratios within sheep erythrocytes and their activity, encapsulation yields and erythrocyte recovery levels were assessed. Encapsulated derivatives were administered at given dosages and at given intervals to sheep having raised blood urea levels as a result of addition of urea to their feed, and the lowering of their blood urea levels and the change in the amount of ammonia were followed. Results were analyzed using day related NPar. Wilcoxon Signet Ranks test. It was found that 1 ml of PEG-enzyme preparation comprising PEG-urease/PEG-AlaDH at an activity ratio of 3/9 U:U/ml remained active for a period of 2 days, whereas 1 ml erythrocyte preparation, prepared under the same conditions and containing PEG-urease/PEG-AlaDH at an activity ratio of 2.15/4.5 U:U/ml, showed activity for a period of 6 days. It was shown that a single dose achieved a daily decrease of 21.7-61.6 mg/L in the blood urea level, and created no significant increase in the blood ammonia levels. No antigenic effect was observed for the PEG-enzyme preparations in the immunological test carried out