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    Öğe
    First protein affinity application of Cu2+-bound pure inorganic nanoflowers
    (Springer, 2022) Onal, Burcu; Acet, Omur; Dzmitruk, Volha; Halets-Bui, Inessa; Shcharbin, Dzmitry; Ozdemir, Nalan; Odabasi, Mehmet
    Today, a new kind of materials is introduced to separation media day by day to increase the efficiency of the separation processes, and multiple-petalled nanostructured materials are one of them. In this study, new pure inorganic copper phosphate nanoflowers (pCP-NFs) were synthesized, and some environmental conditions affecting on binding mechanism with human serum albumin were evaluated via changing medium pH, temperature, initial human serum albumin (HSA) amount and salt concentrations. Before experimental studies, pCP-NFs were subjected to some characterization tests such as scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction and Fourier transform infrared spectroscopy. Besides a lot of valuable instrumental data, some obtained experimental ones as follows: after Cu2+ ions attachment to pCP-NFs as ligand, maximum HSA adsorption capacity of obtained Cu2+-pCP-NFs was found as 225.7 mg/g with an initial concentration of 1.5 mg/mL at pH 7 and 25 degrees C. Langmuir and Freundlich adsorption equations were evaluated for determination of appropriate adsorption model in interaction, and Langmuir model found as the fittest one with a R-2 of 0.9949 was also reviewed to determine Gibbs free energy between HSA and Cu2+-pCP-NFs interaction.
  • [ X ]
    Öğe
    L-asparaginase immobilized p(HEMA-GMA) cryogels: A recent study for biochemical, thermodynamic and kinetic parameters
    (Elsevier Sci Ltd, 2021) Noma, Samir Abbas Ali; Acet, Omur; Ulu, Ahmet; Onal, Burcu; Odabasi, Mehmet; Ates, Burhan
    Cryogels have recently been attracted intense attention as suitable carriers for enzyme immobilization. Herein, L-asparaginase was selected as the model enzyme due to its application such as pharmaceutical and food. Under optimum conditions, L-asparaginase was immobilized on poly (2-hydroxyethyl methacrylate-glycidyl methacrylate) cryogels with 68.8% of immobilization yield and 69.3% of activity recovery. The immobilized enzyme exhibited improved stability with respect to the soluble enzyme at extreme conditions, especially around acidic pH and high temperature. Also, the storage stability and reusability of the immobilized enzyme were found to be approximately 54% and 52% of the original activity after 28 days at room temperature and 10 cycles, respectively. The thermodynamic studies indicated that activation energy (E-a) of the free enzyme decreased from 13.08 to 10.97 kJ/mol, which means an increase in the thermostability of L-asparaginase. The Michaelis-Menten constants (K-m) of 2.04 and 1.67 mM, and the maximum reaction rates (V-max) of 170.0 and 115.0 mu M min(-1) were estimated for soluble and immobilized L-asparaginase, respectively. These findings demonstrated that the designed cryogels turn out to be a good carrier matrix for L-asparaginase immobilization with high catalytic efficiency and enhanced stability.