Studies on the interaction between neutral red and bovine hemoglobin by fluorescence spectroscopy and molecular modeling

The binding interaction of neutral red (NR) with bovine hemoglobin (BHb) was studied by fluorescence spectroscopy in combination with molecular modeling. NR quenched the intrinsic fluorescence of BHb via a static mechanism. According to relevant data, the binding constants were calculated at two different temperatures. The thermodynamic parameters obtained from the fluorescence data showed that the hydrophobic and electrostatic interactions played a major role in stabilizing the complex. Synchronous and three-dimensional fluorescence spectra of BHb were investigated in the presence of NR. The results showed that the environment of tryptophan and tyrosine residues was altered by the dye. The fluorescence experimental results were in agreement with the results obtained by molecular modeling study. (C) 2015 Elsevier B.V. All rights reserved.