金属元素组与血清白蛋白的竞争结合反应性能研究

Study on Competing Reaction of Metallogroup Binding with Serum Albumin

利用亲和毛细管电泳(Affinity capillary electrophoresis,ACE)法研究金属元素组和血清白蛋白(Bovine serum albumin,BSA)的竞争结合反应性能。基于位点结合模型,构建双金属组[Zn2+,Cu2+]与血清白蛋白结合反应模型,建立多元金属组与生物大分子竞争结合的理论方程,测定结合参数并解析动力学机制。结果表明,金属元素组[Zn2+,Cu2+]与BSA发生竞争结合反应形成配合物Zn2+-BSA和Cu2+-BSA。依据有效淌度变化,通过建立的理论方程非线性拟合竞争结合反应的平均表观结合常数KZn2+-BSA=4.01×104L·mol-1、KCu2+-BSA=7.75×104L·mol-1。结合反应均为快平衡反应,Cu2+对Zn2+离子的结合作用有明显拮抗作用。分析ACE谱显示配合物的峰高与配体结合能力大小、配合物稳定性之间存在量效关系。

The performance of competing binding reactions between metallogroup and bovine serum albumin was investigated using affinity capillary electrophoresis（ACE） method. Based on the site binding model, a model about the interaction between [Zn^2＋, Cu^2＋] as the ligand and BSA as the receptor was established, a theoretical equation of competing binding reaction between muhimetal-ions and macromolecule has been suggested, the binding parameters and dynamic mechanism were also measured and analyzed. The result show that, the competitive combined reactions of metallogroup [Zn^2＋, Cu^2＋] with BSA were reacted to form compounds Zn^2＋-BSA and Cu^2＋- BSA. Based on the changes of the effective mobility, the mean apparent competition binding constant was determined through established theoretical equation by using non-linear fitting method, and the average apparent binding constant Kzn^2＋ BSA =4.01 ×10^4 L·mol^-1, K Ca^2＋ BSA=7.75×10^4 L·mol^-1. The binding reactions of Zn^2＋/Cu^2＋-BSA are fast equilibrium reactions, and that Cu^2＋ had antagonism effect on Zn^2＋. Dosage-dependent effect also exists among the peak height of compounds with the ligand strength of binding reactions and stability of compounds.