Investigation and comparison of bovine hemoglobin binding to Al13 and Al(III): Evidences from spectroscopic studies

The UV-vis, steady state/time resolved fluorescence spectroscopy and circular dichroism spectroscopy are employed to investigate the interaction mechanisms of Al-13-Hb and Al(III)-Hb, respectively. The UV-vis studies represent that Al-13 and Al(III) could directly disturb the structure of Hb and induce the home group exposed to the aqueous medium. Steady state/time resolved and synchronous fluorescence spectroscopy reveal that Al-13 and Al(III) can change the polarity around the fluorophore molecule of Hb. Al-13 makes the protein unfolding and Al(III) induces the protein buried inside the structure. The interaction processes are static quenching mechanisms and the main forces are electrostatic interactions. Moreover, circular dichroism spectra display Al-13 makes greater effect than Al(III), which is reflected on the degrees of alpha-helix of Hb. The comparison results suggest that Al-13 displays stronger toxicity. (C) 2012 Elsevier B.V. All rights reserved.