title: Study on the interaction of Co (III) DiAmsar with serum albumins: spectroscopic and molecular docking methods.
abstract: This study was designed to examine the interaction of cobalt-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine (Co(III) DiAmsar) as a hexadentate ligand with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions in Tris-HCl buffer solution at pH 7.4. To this aim, at first, Co (III) DiAmsar was synthesized and characterized by nuclear magnetic resonance (NMR), and mass spectroscopy and then its interaction with HSA and BSA was investigated by means of various spectroscopic methods (Fourier transform infrared (FT-IR), UV-visible (UV-vis), fluorescence, and cyclic voltammetry (CV)) and molecular docking technique. The results of fluorescence titration revealed that the Co (III) DiAmsar strongly quench the intrinsic fluorescence of HSA and BSA through a static quenching procedure. Binding constants (Ka) and the number of binding sites (n∼1) were calculated using Stern-Volmer equations. The ΔG parameters at different temperatures were calculated. Subsequently, the values of ΔH and ΔS were also calculated, which revealed that the van der Waals and hydrogen bonding interaction splay a major role in Co (III) DiAmsar-HSA and Co (III) DiAmsar-BSA associations. The distance r between donor (HSA and BSA) and acceptor (Co (III) DiAmsar) was obtained according to fluorescence resonance energy transfer. The data obtained by the molecular modeling study revealed the surrounding residues of HSA and BSA around Co (III) DiAmsar.
authors.affiliation: Department of Chemistry, Faculty of Science, Imam Khomeini International University, P.O. Box 288, Qazvin 34149, Iran. Electronic address: bvasheghanif@yahoo.com.
authors.forename: Bahman Vasheghani
authors.initials: BV
authors.lastname: Farahani
authors.affiliation: Department of Chemistry, Payame Noor University (PNU), P.O. Box 19395-3697, Tehran, Iran. Electronic address: rezanejad@pnu.ac.ir.
authors.forename: Ghasem Rezanejade
authors.initials: GR
authors.lastname: Bardajee
authors.affiliation: Department of Chemistry, Faculty of Science, Imam Khomeini International University, P.O. Box 288, Qazvin 34149, Iran.
authors.forename: Farzaneh Hosseinpour
authors.initials: FH
authors.lastname: Rajabi
authors.affiliation: Department of Chemistry, Faculty of Science, Imam Khomeini International University, P.O. Box 288, Qazvin 34149, Iran.
authors.forename: Zari
authors.initials: Z
authors.lastname: Hooshyar
mesh_terms: D000818:Animals; D002417:Cattle; D003035:Cobalt / Q000737:chemistry*; D055664:Electrochemical Techniques; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D062105:Molecular Docking Simulation / Q000379:methods*; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics
chemical_list: D006571:Heterocyclic Compounds; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D003035:Cobalt; C059143:diamsar chelate; D012521:Sarcosine
keywords: Co (III) DiAmsar; Fluorescence; Molecular docking; Serum albumin