Iraninan Biology Society Journal of Cellular and Molecular Research (Iranian Journal of Biology) 2383-2738 35 4 2022 12 22 Investigation of the Fe2O3 nanoparticles interaction with human serum albumin using fluorescence and circular dichroism (CD) techniques Investigation of the Fe2O3 nanoparticles interaction with human serum albumin using fluorescence and circular dichroism (CD) techniques 521 533 2068 FA Ali Riahi-Madvar Dept. of Molecular and Cell Biology, Faculty of Basic Sciences, Kosar University of Bojnord, Bojnord, I.R. of Iran. Alireza Ghaseminasab Dept. of Biotechnology, Faculty of Science and Modern Technology, Technology and Advanced Technology University, Kerman, I.R. of Iran. Farshid Barzegary-Dehaj Dept. of Biotechnology, Institute of Science and High technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, I.R. of Iran. Zahra Zamani Dept.of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, I.R. of Iran. Fatemeh Rezaee Dept. of Biology, Faculty of science, Ferdowsi University of Mashhad, Mashhad, I.R. of Iran. Journal Article 2021 04 03 Nanoparticles (NPs) have broad applications in various industries, that it can be expected them find a way to enter into the environment and affected the living organism with unexpected consequences. According to the broad applications of the Fe2O3 nanoparticles (nFe2O3) in different industries, in this study, its interaction with human serum albumen (HSA), as an abundant protein in blood, was investigated using intrinsic fluorescence at different temperature ranges, extrinsic fluorescence and circular dichroism (CD) methods. Results showed, with increasing NP concentration in media, intrinsic fluorescence intensity of the protein decreased in all temperatures. Based on the quenching rate constant (Kq), it revealed that interaction between HAS and nFe2O3 take place through static mechanism. Thermodynamic parameters indicate the sign of enthalpy and entropy are negative, which implies the role of hydrogen bands and Van der Waals forces in this interaction. The negative sign of free energy (∆G°), revealed this reaction is exergonic and spontaneously. On the other hand, ANS fluorescence intensity increased more for HSA in interaction with NP in contrast to the ANS. Furthermore, Far-UV CD spectra shows an alteration in the secondary structure of this protein in interaction with the NP. The results all together revealed changes in the structure of HSA upon exposed to this nanoparticle which can affected its performance. Nanoparticles (NPs) have broad applications in various industries, that it can be expected them find a way to enter into the environment and affected the living organism with unexpected consequences. According to the broad applications of the Fe2O3 nanoparticles (nFe2O3) in different industries, in this study, its interaction with human serum albumen (HSA), as an abundant protein in blood, was investigated using intrinsic fluorescence at different temperature ranges, extrinsic fluorescence and circular dichroism (CD) methods. Results showed, with increasing NP concentration in media, intrinsic fluorescence intensity of the protein decreased in all temperatures. Based on the quenching rate constant (Kq), it revealed that interaction between HAS and nFe2O3 take place through static mechanism. Thermodynamic parameters indicate the sign of enthalpy and entropy are negative, which implies the role of hydrogen bands and Van der Waals forces in this interaction. The negative sign of free energy (∆G°), revealed this reaction is exergonic and spontaneously. On the other hand, ANS fluorescence intensity increased more for HSA in interaction with NP in contrast to the ANS. Furthermore, Far-UV CD spectra shows an alteration in the secondary structure of this protein in interaction with the NP. The results all together revealed changes in the structure of HSA upon exposed to this nanoparticle which can affected its performance. https://cell.ijbio.ir/article_2068_814a9c18f5abff398787c9cfcbf3d80c.pdf