2026-10-23T22:56:56Zhttps://gumushane-rdlopen.rawdatalibrary.net/oai/requestoai:gumushane-rdlopen.rawdatalibrary.net:gumushane/128342026-10-23T21:02:40Zopenairedrivercom_gumushane_10000col_gumushane_10001com_gumushane_10010col_gumushane_10172Different spacer-arm attached magnetic nanoparticles for covalent immobilization of Jack bean ureaseGulesci, NuriYucebilgic, GuzideYildirim, Denizepichlorohydringlutaraldehydeimmobilizationmagnetic nanoparticlesureaseObjectives: This study aims the covalent immobilization of Jack bean urease on Fe3O4 magnetic nanoparticles via glutaraldehyde (urease@MNPs-Si-Glu) and epichlorohydrin (urease@MNPs-ECH) spacer arms. Methods: The optimum pH and temperature, thermal, storage and reuse stability of free and immobilized urease preparations were investigated. Thermodynamics characterizations of free and immobilized urease preparations were also studied. Results: The free urease and both immobilized urease preparations showed maximal catalytic activity at pH 7.5. The free urease had a maximal catalytic activity at 50 °C, while the both immobilized urease preparations exhibited their maximal catalytic activities at 70 °C. The urease@MNPs-Si-Glu and urease@MNP-ECH showed 2.7- and 1.9-fold higher thermal stability than the free urease at 60 °C, respectively. The free urease remained 30% of their initial activity at 4 °C, while urease@MNPs-Si-Glu and urease@MNPs-ECH retained 72 and 60% of their initial activities at the same conditions. The urease@MNPs-Si-Glu and urease@MNPs-ECH preserved 53 and 52% of their initial activities, respectively for urea hydrolysis after 20 reuses. Conclusions: The urease@MNPs-Si-Glu and urease@MNPsECH may find a potential application area in urea hydrolysis.De Gruyter Open Ltd2022Articlehttps://rdlopen.rawdatalibrary.net/r/gumushane/12834https://doi.org/10.1515/tjb-2021-02640250-4685enTurkish Journal of Biochemistryinfo:eu-repo/semantics/openAccessinfo:eu-repo/semantics/articlehttps://gumushane-rdlopen.rawdatalibrary.net/tr/items/gumushane/12834