Landau M A, Markovich M N, Piruzyan L A
Biochim Biophys Acta. 1977 Jul 22;493(1):1-9. doi: 10.1016/0005-2795(77)90255-0.
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.
本文提出了通过量热法测定蛋白质分子表面均匀独立结合位点数量的可能性，以及测定小分子与一个这样的位点结合的相互作用热和缔合常数的可能性。利用该技术获得了10种青霉素和甲基橙与牛血清白蛋白一级和二级结合位点相互作用的热力学特征。数据表明，所研究的复合物各组成部分之间不存在氢键。形成这些复合物时自由能变化的主要贡献来自疏水相互作用。静电力也有一定重要性，对于具有额外带电羧基的喹那西林和羧苄西林，它们对复合物形成的贡献更为显著。
