title: Spectroscopic and theoretical investigation of oxali-palladium interactions with β-lactoglobulin.
abstract: The possibility of using a small cheap dairy protein, β-lactoglobulin (β-LG), as a carrier for oxali-palladium for drug delivery was studied. Their binding in an aqueous solution at two temperatures of 25 and 37°C was investigated using spectroscopic techniques in combination with a molecular docking study. Fluorescence intensity changes showed combined static and dynamic quenching during β-LG oxali-palladium binding, with the static mode being predominant in the quenching mechanism. The binding and thermodynamic parameters were determined by analyzing the results of quenching and those of the van't Hoff equation. According to obtained results the binding constants at two temperatures of 25 and 37°C are 3.3×10(9) M(-1) and 18.4×10(6) M(-1) respectively. Fluorescence resonance energy transfer (FRET) showed that the experimental results and the molecular docking results were coherent. An absence change of β-LG secondary structure was confirmed by the CD results. Molecular docking results agreed fully with the experimental results since the fluorescence studies also revealed the presence of two binding sites with a negative value for the Gibbs free energy of binding of oxali-palladium to β-LG. Furthermore, molecular docking and experimental results suggest that the hydrophobic effect plays a critical role in the formation of the oxali-palladium complex with β-LG. This agreement between molecular docking and experimental results implies that docking studies may be a suitable method for predicting and confirming experimental results, as shown in this study. Hence, the combination of molecular docking and spectroscopy methods is an effective innovative approach for binding studies, particularly for pharmacophores.
authors.affiliation: Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Behafarid
authors.initials: B
authors.lastname: Ghalandari
authors.forename: Adeleh
authors.initials: A
authors.lastname: Divsalar
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Saboury
authors.forename: Thomas
authors.initials: T
authors.lastname: Haertlé
authors.forename: Kazem
authors.initials: K
authors.lastname: Parivar
authors.forename: Roya
authors.initials: R
authors.lastname: Bazl
authors.forename: Mahbube
authors.initials: M
authors.lastname: Eslami-Moghadam
authors.forename: Massoud
authors.initials: M
authors.lastname: Amanlou
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D056831:Coordination Complexes / Q000737:chemistry* / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D007782:Lactoglobulins / Q000737:chemistry / Q000378:metabolism*; D062105:Molecular Docking Simulation; D010165:Palladium / Q000737:chemistry* / Q000494:pharmacology; D013816:Thermodynamics
chemical_list: D056831:Coordination Complexes; D007782:Lactoglobulins; D010165:Palladium
keywords: 8-anilino-1-naphthalenesulfonate; ANS; CD; FRET; GA; MRW; Molecular docking; Oxali–palladium; Static quenching; Thermodynamic parameter; circular dichroism; fluorescence resonance energy transfer; genetic algorithm; mean amino acid residue weight; β-LG; β-lactoglobulin