title: Comprehensive study on the structure of the BSA from extended-to aged form in wide (2-12) pH range.
abstract: In this work we studied the structure of the bovine serum albumin (BSA) and the protein-ligand interactions since researchers prefer to use them as carriers in drug delivery systems. Systematic study (between pH 2-12, in double distilled water and physiological salt solution) was carried out to determine the changes in the secondary and the tertiary structures of the BSA, the apparent molecular weight (Mw), the size (dLS) and the electrokinetic potential (ζ). At pH 7, the BSA has higher stability in the absence (ζ=-69mV, dLS=2.2nm, A2=1.4×10(-3)mlmol/g(2)) than in the presence of salt solution (ζ=-2.4mV, dLS=5.3nm, A2=-3.2×10(-4)mlmol/g(2)). The Mw strongly depends on the pH and the ionic strength (at pH 3 in the absence of salt, the Mw is 54.6kDa while in the presence of salt is 114kDa) which determines the geometry of the protein. The protein-ligand interactions were characterized by fluorescence (FL) and isothermal microcalorimetry (ITC) methods; these independent techniques provided similar thermodynamic parameters such as the binding constant (K) and the Gibbs free energy (ΔG).
authors.affiliation: Department of Physical Chemistry and Materials Sciences, University of Szeged, H-6720 Aradi Vt. tere 1, Szeged, Hungary.
authors.forename: N
authors.initials: N
authors.lastname: Varga
authors.affiliation: Department of Physical Chemistry and Materials Sciences, University of Szeged, H-6720 Aradi Vt. tere 1, Szeged, Hungary.
authors.forename: V
authors.initials: V
authors.lastname: Hornok
authors.affiliation: Department of Physical Chemistry and Materials Sciences, University of Szeged, H-6720 Aradi Vt. tere 1, Szeged, Hungary.
authors.forename: D
authors.initials: D
authors.lastname: Sebők
authors.affiliation: MTA-SZTE Supramolecular and Nanostructured Materials Research Group, Department of Medical Chemistry, Faculty of Medicine, University of Szeged, H-6720 Dóm tér 8, Szeged, Hungary. Electronic address: i.dekany@chem.u-szeged.hu.
authors.forename: I
authors.initials: I
authors.lastname: Dékány
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D000818:Animals; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D007660:Ketoprofen / Q000737:chemistry; D008024:Ligands; D008970:Molecular Weight; D009994:Osmolar Concentration; D017510:Protein Folding; D055550:Protein Stability; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D058767:Protein Unfolding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D055672:Static Electricity; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D000817:Anilino Naphthalenesulfonates; D008024:Ligands; D014867:Water; D012710:Serum Albumin, Bovine; D012965:Sodium Chloride; C027132:1-anilino-8-naphthalenesulfonate; D007660:Ketoprofen
keywords: BSA; Conformation; Fluorescence; Geometry; Microcalorimetry; pH