In this study, matrix entrapment of the enzyme glucose oxidase was achieved through gamma-irradiation of monomers N-vinyl pyrrolidone, 2-hydroxyethyl methacrylate and their mixture. To test the effect of radiation on entrapment efficiency, retention of activities and properties of the system, duration and temperature were varied. The reusability of the resultant products was tested. It was generally found that inclusion of the hydrophilic monomer N-vinyl pyrrolidone into the matrix increased the water content, entrapment efficiency and enzyme activity. Gamma-irradiation did not have a detrimental effect on the activity of pure enzyme when exposure was at -196-degrees-C, but this radioresistance was less at higher temperatures. Infrared spectroscopy indicated that there was no chemical binding between the matrix and the enzyme. Repeated use studies revealed a gradual loss of activity in all of the samples tested for 10 runs.


Solid-phase enzyme modification via affinity chromatography
Baran, ET; Ozer, N; Hasırcı, Vasıf Nejat (2003-09-05)
In the present study antileukemic enzyme L-asparaginase (ASNase) and catalase (as a model enzyme) were modified in solid-phase with activated polyethylene glycol (PEG,) by using ligand-immobilized affinity column systems L-asparagine-Sepharose CL-4B and Procion red-Sepharose CL-4B, respectively. Studies on change of specific activity with modification time showed negligible differences between batches of modified catalase. Modification of ASNase for I It resulted in 50.2% recovery of the specific activity a...
Preparation of Chitosan-Coated Magnetite Nanoparticles and Application for Immobilization of Laccase
Kalkan, Nuzhet Ayca; AKSOY, SERPİL; Aksoy, Eda Ayse; Hasırcı, Nesrin (2012-01-15)
In this study, immobilization of laccase (L) enzyme on magnetite (Fe(3)O(4)) nanoparticles was achieved, so that the immobilized enzyme could be used repeatedly. For this purpose, Fe(3)O(4) nanoparticles were coated and functionalized with chitosan (CS) and laccase from Trametes versicolor was immobilized onto chitosan-coated magnetic nanoparticles (Fe(3)O(4)-CS) by adsorption or covalent binding after activating the hydroxyl groups of chitosan with carbodiimide (EDAC) or cyanuric chloride (CC). For chitosa...
Benzoylformate decarboxylase from Pseudomonas putida as stable catalyst for the synthesis of chiral 2-hydroxy ketones
Iding, H; Dunnwald, T; Greiner, L; Liese, A; Muller, M; Siegert, P; Grotzinger, J; Demir, Ayhan Sıtkı; Pohl, M (2000-04-14)
The thiamin diphosphate- and Mg2+-dependent enzyme benzoylformate decarboxylase (BFD) from Pseudomonas putida was characterized with respect to its suitability to catalyze the formation of chiral 2-hydroxy ketones in a benzoin-condensation type reaction. Carboligation constitutes a side reaction of BFD, whereas the predominant physiological task of the enzyme is the non-oxidative decarboxylation of benzoylformate. For this purpose the enzyme was obtained in sufficient purity from Pseudomonas putida cells in...
Preparation and Characterization of Amino-Functionalized Zeolite/SiO2 Materials for Trypsin-Chymotrypsin Co-immobilization
Dogan, Demet; Sezer, Selda; Ulu, Ahmet; KÖYTEPE, SÜLEYMAN; ATEŞ, BURHAN (2021-08-01)
Inorganic supports have attracted increased attention in enzyme immobilization since they not only improve enzyme stability but also reduce the final cost of enzymatic reactions. Herein, we explored the suitability of the amino-functionalized zeolite/SiO2 materials to co-immobilize trypsin-chymotrypsin mixture. For this purpose, the trypsin-chymotrypsin mixture was co-immobilized on the amino-functionalized zeolite/SiO2 materials and the immobilization yield was 80.7 +/- 7.6%. The pre-support and its modifi...
Immobilization of invertase and glucose oxidase in conducting H-type polysiloxane/polypyrrole block copolymers
Gursel, A; Alkan, S; Toppare, Levent Kamil; Yagci, Y (Elsevier BV, 2003-01-01)
In this study, immobilizations of enzymes, invertase and glucose oxidase, were achieved in conducting copolymers of N-pyrrolyl terminated polydimethylsiloxane/polypyrrole (PDMS/PPy) matrices via electrochemical polymerization. The kinetic parameters, v(max) (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on enzyme activity and film morphologies was examined. ...
Citation Formats
I. GURSEL and V. N. Hasırcı, “MATRIX ENTRAPMENT OF GLUCOSE-OXIDASE BY GAMMA-IRRADIATION,” BIOMATERIALS, pp. 150–155, 1992, Accessed: 00, 2020. [Online]. Available: