title: A Spectroscopic Approach to Investigate the Molecular Interactions between the Newly Approved Irreversible ErbB blocker "Afatinib" and Bovine Serum Albumin.
abstract: The interaction of afatinib (AFB) with bovine serum albumin (BSA) was examined via fluorescence and UV-Vis spectroscopy. Spectrofluorimetric measurements revealed that AFB can strongly quench the BSA intrinsic fluorescence through producing a non-fluorescent complex. This quenching mechanism was thoroughly investigated with regard to the type of quenching, binding constant, number of binding locations and the fundamental thermodynamic parameters. Subsequently, the association constant of AFB with BSA was computed at three different temperatures and was found to range from 7.34 to 13.19 x10(5) L mol(-1). Thermodynamic parameters calculations demonstrated a positive ΔSƟ value with both negative ΔHϴ and ΔGϴ values for AFB-BSA complex, which in turn infers that a spontaneous binding is taking place with both electrostatic bonding and hydrophobic interactions participating in the binding of AFB and BSA. Similarly, the UV absorption spectra of AFB-BSA system were studied and confirmed the interaction. Conformational alteration of the protein upon binding to AFB was elaborated with the aid of three dimensional fluorescence measurements as well as synchronous fluorescence spectra.
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia.
authors.forename: Amer M
authors.initials: AM
authors.lastname: Alanazi
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia.
authors.forename: Ali Saber
authors.initials: AS
authors.lastname: Abdelhameed
mesh_terms: D000077716:Afatinib; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D008027:Light; D008958:Models, Molecular; D018739:Oncogene Proteins v-erbB / Q000037:antagonists & inhibitors* / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011799:Quinazolines / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D013696:Temperature; D013816:Thermodynamics
chemical_list: D018739:Oncogene Proteins v-erbB; D011799:Quinazolines; D012710:Serum Albumin, Bovine; D000077716:Afatinib; D011505:Protein-Tyrosine Kinases