Fluorescence spectroscopic study on the interaction of resveratrol with lipoxygenase

The interaction of lipoxygenase with (E)-resveratrol was investigated by fluorescence spectroscopy. The data obtained revealed that the quenching of intrinsic fluorescence of lipoxygenase is produced by the formation of a complex lipoxygenase-(E)-resveratrol. From the value obtained for the binding constant, according to the Stern-Volmer modified equation, was deduced the existence of static quenching mechanism and, as consequence, the existence of a strong interaction between (E)-resveratrol and lipoxygenase. The values obtained for the thermodynamic parameter Delta H (-3.58 kj mol(-1)) and Delta S (87.97J mol(-1)K(-1)) suggested the participation of hydrophobic interactions and hydrogen bonds in the stabilization of the complex ligand-protein. From the static quenching we determined that only exist one independent binding site. Based on the Forster energy transfer theory, the distance between the acceptor ((E)-resveratrol) and the donor (Trp residues of lipoxygenase) was calculated to be 3.42 nm. Finally, based on the information obtained from the evaluation of synchronous and three-dimensional fluorescence spectroscopy, we deduced that the interaction of (E)-resveratrol with lipoxygenase produces micro-environmental and conformational alterations of protein in the binding region. (C) 2010 Elsevier B.V. All rights reserved.