title: Spectroscopic studies and life time measurements of binding of a bioactive compound to bovine serum albumin and the effects of common ions and other drugs on binding.
abstract: The mechanism of binding of anti-inflammatory drug, nimesulide (NIM) with bovine serum albumin (BSA) was investigated by fluorescence, absorption, circular dichroism (CD) and lifetime measurements under simulative physiological conditions. The analysis of fluorescence data indicated the presence of both dynamic and static quenching mechanism in the binding. Various binding parameters have been evaluated. The CD spectral data revealed the decrease in alpha-helical content of BSA from 70.9% (in free BSA) to 42.03% (in bound form) thereby indicating the conformational change in BSA upon binding. The binding of NIM to BSA was also confirmed by absorption spectra. Based on the Förster's theory of non-radiation energy transfer, the binding average distance, r between the donor (BSA) and acceptor (NIM) was found to be 2.17 nm. The association constants of NIM-BSA decreased in presence of the common ions and other drugs thereby indicating the availability of higher concentration of free drug (NIM) in plasma.
authors.affiliation: Department of Chemistry, Karnatak University, Dharwad, India.
authors.forename: Sarfaraj Mohd Takhi
authors.initials: SM
authors.lastname: Shaikh
authors.forename: Jaldappa
authors.initials: J
authors.lastname: Seetharamappa
authors.forename: Siddaramanna
authors.initials: S
authors.lastname: Ashoka
authors.forename: Pradeep Basavaraj
authors.initials: PB
authors.lastname: Kandagal
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis / Q000378:metabolism*; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism / Q000379:methods; D004347:Drug Interactions; D007477:Ions / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013449:Sulfonamides / Q000032:analysis / Q000378:metabolism*; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007477:Ions; D013449:Sulfonamides; D012710:Serum Albumin, Bovine; C012655:nimesulide