title: Binding interaction of a biological photosensitizer with serum albumins: a biophysical study.
abstract: 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 performed using a combination of steady-state and time-resolved fluorescence techniques. The emission profile undergoes a remarkable change upon addition of the proteins to the buffered aqueous solution of the photosensitizer. The polarity-dependent prototropic transformation is responsible for the remarkable sensitivity of this biological fluorophore to the protein environments. A marked increase in the fluorescence anisotropy in the proteinous environments indicates that the albumin proteins introduce motional restriction on the drug molecule. Light has been thrown on the denaturing action of urea on the probe-bound protein. The probable binding site of the drug in proteins has also been assessed from the combination of denaturation study, micropolarity measurement, and fluorescence resonance energy transfer (FRET) study. The present study suggests that the stability of serum albumins is enhanced upon binding with the drug.
authors.affiliation: Department of Chemistry, Jadavpur University, Calcutta-700 032, India.
authors.forename: Alok
authors.initials: A
authors.lastname: Chakrabarty
authors.forename: Arabinda
authors.initials: A
authors.lastname: Mallick
authors.forename: Basudeb
authors.initials: B
authors.lastname: Haldar
authors.forename: Paramita
authors.initials: P
authors.lastname: Das
authors.forename: Nitin
authors.initials: N
authors.lastname: Chattopadhyay
mesh_terms: D000818:Animals; D016880:Anisotropy; D001703:Biophysics / Q000379:methods*; D002412:Cations; D002417:Cattle; D002942:Circular Dichroism; D006801:Humans; D046911:Macromolecular Substances / Q000737:chemistry; D010777:Photochemistry / Q000379:methods; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D011489:Protein Denaturation; D017510:Protein Folding; D012709:Serum Albumin / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D002412:Cations; D046911:Macromolecular Substances; D017319:Photosensitizing Agents; D012709:Serum Albumin; D012710:Serum Albumin, Bovine