文摘
A photophysical study on the binding interaction of an efficient cancer cell photosensitizer, norharmane (NHM),with model transport proteins, bovine serum albumin (BSA) and human serum albumin (HSA), has been performedusing a combination of steady-state and time-resolved fluorescence techniques. The emission profile undergoesa remarkable change upon addition of the proteins to the buffered aqueous solution of the photosensitizer. Thepolarity-dependent prototropic transformation is responsible for the remarkable sensitivity of this biologicalfluorophore to the protein environments. A marked increase in the fluorescence anisotropy in the proteinousenvironments indicates that the albumin proteins introduce motional restriction on the drug molecule. Light hasbeen thrown on the denaturing action of urea on the probe-bound protein. The probable binding site of the drugin proteins has also been assessed from the combination of denaturation study, micropolarity measurement, andfluorescence resonance energy transfer (FRET) study. The present study suggests that the stability of serum albuminsis enhanced upon binding with the drug.
