Interaction of Retinol with HSA using Spectroscopic Techniques

The interaction between retinol and HSA has been investigated using UV-absorption spectrophotometry, fluorescence spectroscopy and Fourier Transform Infrared (FT-IR) spectroscopy. UV-absorption spectrophotometry showed an increase in the absorption intensity with increasing the molecular ratios of retinol to HSA, it is found that the value of the binding constant is estimated to be 1.7176102 M-1. FTIR spectroscopy is used in the mid infrared region with Fourier self deconvolution, second derivative, difference spectra, peak picking and curve fitting were used to determine the effect of Retinol on the protein secondary structure in the amides I, II and Ill regions. Analysis of FTIR absorbance spectra is found that the intensity of the absorption bands increased with increasing the molecular ratios of retinol, however from the deconvoluted and curve fitted spectra found that the absorbance intensity for -helix decreases relative to -sheets, this decrease in intensity is related to the formation of H- bonding in the complex molecules.