title: Fluorescence quenching study on the interaction between quercetin and lipoxygenase.
abstract: The interaction between quercetin and lipoxygenase was investigated by fluorescence spectroscopy. The analysis of the emission quenching at different temperatures revealed that the quenching mechanism correspond to a static process and, as consequence, a complex quercetin-lipoxygenase is formed. The thermodynamic parameters ΔG, ΔH and ΔS were calculated to be-32.57 kJ mol(-1),-3.21 kJ mol(-1) and 87.14 J mol(-1) K(-1) respectively, which suggest that hydrophobic forces plays a major role in the stabilization of the complex quercetin-lipoxygenase. The distance, r, between donor (lipoxygenase) and acceptor (quercetin) was calculated to be 3.84 nm based on Förster's non-radiative energy transfer theory. The results obtained from the evaluation of three dimensional florescence spectra suggest a conformational modification of the protein in the region of the coupling with quercetin.
authors.affiliation: Department of Biochemistry and Molecular Biology, Faculty of Sciences, Extremadura University, Av. Elvas s/n, 06006, Badajoz, Spain.
authors.forename: María Del Carmen
authors.initials: Mdel C
authors.lastname: Pinto
authors.forename: Antonio Luis
authors.initials: AL
authors.lastname: Duque
authors.forename: Pedro
authors.initials: P
authors.lastname: Macías
mesh_terms: D004735:Energy Transfer; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D057927:Hydrophobic and Hydrophilic Interactions; D008084:Lipoxygenase / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D011794:Quercetin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013816:Thermodynamics
chemical_list: D011794:Quercetin; D008084:Lipoxygenase