title: Studies of the thermodynamics and nature of interaction between serum albumin and penicillins.
abstract: The possibility of a calorimetric determination of the number of homogeneous independent binding sites on the protein molecule surface is presented, together with the possibility of the determination of interaction heat and association constants for the binding of small molecules to one such site. Thermodynamic characteristics of interaction of 10 penicillins and methyl orange with primary and secondary binding sites of bovine serum albumin have been obtained using this technique. The data show that hydrogen bonds between the component parts of the complexes studied are absent. The main contribution to free energy change at forming these complexes is made by hydrophobic interactions. Electrostatic forces are also of some importance, their contribution into the complex formation is more significant in the case of quinacillin and carbenicillin which have an additional charged carboxyl group.
mesh_terms: D001665:Binding Sites; D002151:Calorimetry; D007700:Kinetics; D008433:Mathematics; D010406:Penicillins; D011485:Protein Binding; D012710:Serum Albumin, Bovine; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D010406:Penicillins; D012710:Serum Albumin, Bovine