title: A spectroscopic study on the absorption of carbonic anhydrase onto the nanoporous silica nanoparticle.
abstract: Herein, KIT-6 nanoporous silica nanoparticles were used as a solid support for immobilization of bovine carbonic anhydrase, isoform II (BCA II). The zeta potential study revealed that KIT-6 and BCA II provided negative (-13.58±1.95mV) and positive (4.23±0.72mV) charge distribution, respectively. Dynamic light scattering (DLS) analysis also showed that the hydrodynamic radius of KIT-6 is less than 100nm. In addition, the structural studies of free and immobilized BCA II against urea-induced denaturation were investigated by circular dichroism (CD) and fluorescence spectroscopy. CD studies showed that the absorbed BCA II, in comparison with the free enzyme, demonstrated higher stability against rising urea concentration. Fluorescence spectroscopy showed lower values of Stern- Volmer constant (KSV) for immobilized BCA II relative to free enzyme, reflecting the relative enzyme stability of BCA II after immobilization. Melting temperature (Tm) measurement of free and immobilized BCA II showed that immobilized enzyme had a more stable structure (Tm=71.9°C) relative to the free counterpart (Tm=64.7°C). In addition, the immobilized BCA II showed pronounced stability against pH and thermal deactivation. This study may provide new and complementary details regarding the design and development of enzymes in industrial applications.
authors.affiliation: Department of Nanotechnology, Faculty of Advance Science and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.
authors.forename: Hannaneh Pourjabbari
authors.initials: HP
authors.lastname: Khameneh
authors.affiliation: Department of Biotechnology, Faculty of Advance Science and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.
authors.forename: Termeh Ghorbanian
authors.initials: TG
authors.lastname: Bolouri
authors.affiliation: Department of Biotechnology, Faculty of Advance Science and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Nemati
authors.affiliation: Department of Nanotechnology, Faculty of Advance Science and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rezvani
authors.affiliation: Department of Biology, Faculty of Food Industry & Agriculture, Standard Research Institute (SRI), Karaj, Iran.
authors.forename: Farnoosh
authors.initials: F
authors.lastname: Attar
authors.affiliation: Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Saboury
authors.affiliation: Department of Nanotechnology, Faculty of Advance Science and Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran. Electronic address: falahati@ibb.ut.ac.ir.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Falahati
mesh_terms: D000327:Adsorption; D000818:Animals; D055162:Biocatalysis; D024402:Carbonic Anhydrase II / Q000737:chemistry* / Q000378:metabolism; D002417:Cattle; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013057:Spectrum Analysis; D044366:Transition Temperature
chemical_list: D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D024402:Carbonic Anhydrase II
keywords: Carbonic anhydrase; Circular dichroism; Enzyme activity; Fluorescence spectroscopy; Immobilization; Quenching