Biomolecular interactions of selected buffers with hemoglobin

To elucidate the influence of commonly used biological buffers on the hemoglobin (Hb) structure, biomolecular interactions between Hb and the selected buffers, including tris (hydroxymethyl) aminomethane (TRIS), N -[tris (hydroxymethyl) methyl]-3-aminopropanesulfonic acid (TAPS) and N -[tris (hydroxymethyl) methyl]-2-aminoethane-sulfonic-acid (TES), are investigated by using various biophysical spectroscopic and other techniques. The techniques used in this study are ultraviolet–visible (UV–Vis), fluorescence, circular dichroism (CD) and Fourier transform infrared spectroscopy and dynamic light scattering. Fluorescence spectra analysis reveals that the addition of biological buffers increases the hydrophobicity around the tryptophan environment in Hb. Evidently, the alpha-helix structure of Hb was slightly destroyed at higher concentrations of the buffers detected by CD spectroscopy. However, the thermal stability of the protein transition temperature ( T m ) gradually increases with an increase in the concentration of the biological buffers. The results also show that generally the biological buffers are able to enhance the stability of Hb. Graphic abstract