Yazarlar
Yayınlar
- MakaleAçık Erişim2022Different spacer-arm attached magnetic nanoparticles for covalent immobilization of Jack bean urease
Gulesci, Nuri; Yucebilgic, Guzide; Yildirim, Deniz
Objectives: 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.
- MakaleYalnız künye2018Investigation of the inhibitory effects of human carbonic anhydrase i and jack bean urease by coumarin derivates
Aygul, Imdat; Karahalil, Fatma Yaylaci; Danis, Ozkan; Ogan, Ayse; Kolayli, Sevgi
Introduction: This study investigated the in vitro inhibition properties of newly synthesized coumarin derivates (C1-C5) against human carbonic anhdyrase I (hCA-I) and jack bean urease. Activities were expressed as IC50 (mg/mL), the concentration reducing 50% of the enzymes. The IC50 values for hCA-I ranged 5.20 µM from 12.10 µM, with compound C3 exhibiting the highest activity. The inhibition values for urease ranged 22.30 µM to 39.00 µM, the highest activity being observed in C5. Conclusion: Comparing the inhibitions with standard inhibitors of the enzymes, while the samples exhibited moderate inhibitions against hCA I, high inhibition was determined against urease.