title: Probing the conformational changes and peroxidase-like activity of cytochrome c upon interaction with iron nanoparticles.
abstract: Herein, the interaction of iron nanoparticle (Fe-NP) with cytochrome c (Cyt c) was investigated, and a range of techniques such as dynamic light scattering (DLS), zeta potential measurements, static and synchronous fluorescence spectroscopy, near and far circular dichroism (CD) spectroscopy, and ultraviolet-visible (UV-vis) spectroscopy were used to analyze the interaction between Cyt c and Fe-NP. DLS and zeta potential measurements showed that the values of hydrodynamic radius and charge distribution of Fe-NP are 83.95 ± 3.7 nm and 4.5 ± .8 mV, respectively. The fluorescence spectroscopy results demonstrated that the binding of Fe-NP with Cyt c is mediated by hydrogen bonds and van der Waals interactions. Also Fe-NP induced conformational changes in Cyt c and reduced the melting temperature value of Cyt c from 79.18 to 71.33°C. CD experiments of interaction between Fe-NP and Cyt c revealed that the secondary structure of Cyt c with the dominant α-helix structures remained unchanged whereas the tertiary structure and heme position of Cyt c are subjected to remarkable changes. Absorption spectroscopy at 695 nm revealed that Fe-NP considerably disrupt the Fe…S(Met80) bond. In addition, the UV-vis experiment showed the peroxidase-like activity of Cyt c upon interaction with Fe-NP. Hence, the data indicate the Fe-NP results in unfolding of Cyt c and subsequent peroxidase-like activity of denatured species. It was concluded that a comprehensive study of the interaction of Fe-NP with biological system is a crucial step for their potential application as intracellular delivery carriers and medicinal agents.
authors.affiliation: a Faculty of Advance Science and Technology, Department of Nanotechnology , Islamic Azad University (IAUPS) , Pharmaceutical Sciences Branch, Tehran , Iran.
authors.forename: Vida
authors.initials: V
authors.lastname: Jafari Azad
authors.affiliation: b Biology Department , Islamic Azad University , Tehran Medical Sciences Branch, Tehran , Iran.
authors.forename: Shahab
authors.initials: S
authors.lastname: Kasravi
authors.affiliation: c Brain Engineering Research Center , Institute for Research in Fundamental Sciences (IPM) , P.O.Box 19395-5746, Tehran , Iran.
authors.forename: Hojjat
authors.initials: H
authors.lastname: Alizadeh Zeinabad
authors.affiliation: a Faculty of Advance Science and Technology, Department of Nanotechnology , Islamic Azad University (IAUPS) , Pharmaceutical Sciences Branch, Tehran , Iran.
authors.forename: Mehri
authors.initials: M
authors.lastname: Memar Bashi Aval
authors.affiliation: d Institute of Biochemistry and Biophysics, University of Tehran , Tehran , Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Saboury
authors.affiliation: e Faculty of Basic Science, Department of Biophysics , Islamic Azad University , Science and Research Branch, Tehran , Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Rahimi
authors.affiliation: a Faculty of Advance Science and Technology, Department of Nanotechnology , Islamic Azad University (IAUPS) , Pharmaceutical Sciences Branch, Tehran , Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Falahati
mesh_terms: D000818:Animals; D002417:Cattle; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism*; D000067493:Dynamic Light Scattering; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010544:Peroxidases / Q000378:metabolism*; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence
chemical_list: D045304:Cytochromes c; D007501:Iron; D010544:Peroxidases
keywords: activity; conformational change; nanoparticle; protein; secondary structure