Fluorescent Probing of Urea-induced Chemical Unfolding of Bovine Serum Albumin by Intramolecular Charge Transfer Fluorescence Probe E-3-(4-Dimethylamino-Naphthalen-1-yl)-Acrylic Acid

Changes in polarity at the immediate binding site in protein bovine serum albumin (BSA) produces distinct changes in the solvent polarity-dependent emission band of fluorescence probe E-3-(4-dimethylamino-naphthalen-1-yl)-acrylic acid. Steady-state spectroscopy and time-resolved spectroscopy have been used to investigate this binding process. Attaching the probe to BSA and then monitoring its spectral changes with increasing urea concentration and raising temperature has also tracked the denaturation of BSA chemically and thermally. The polarity of the microenvironment was investigated employing the Reichardt E_T(30) scale. Fluorescence anisotropy, red edge excitation shifts and acrylamide-induced quenching of fluorescence have been exploited to gain better insight into this binding process.