维甲酸结合蛋白的分子可及性与该蛋白和配体相互作用的关系的研究

RESEARCH ON THE RELATIONSHIP BETWEEN THE ACCESSIBILITY OF ERABP AND ITS INTERACTION WITH THE LIGAND

从蛋白质可及性分析的角度研究了ＥＲＡＢＰ与ＲＡ的相互作用模式，在原子水平和残基水平上计算了四个与维甲酸结合蛋白（ＥＲＡＢＰ）有关的分子的可及性，这四个分子是ＥＰＡ（无配体结晶生成的ＥＲＡＢＰ），ＥＰＢ—ＲＡ（ＥＲＡＢ和配体雏甲酸ＲＡ，并对其进行分析比较。分析结果表明，ＲＡ在结合蛋白中采取β－芷香酮环向里，羧基端向外的构象形式；围绕结合部位有２４个残基；在结合配体ＲＡ时，在结合配体ＲＡ时，结合蛋白将发生构象变化，变化的结果是结合部位空穴的暴露程度增大。

This work studied the interaction pattern of Epididymal Retinoic Add Binding Protein (ERABP) and Retinoic Add (RA) by calculating and analysing the accessibility of four molecules at the atomic and residual level. The four molecules are EPA (ERABP crystallizedwithout ligand), EPB (ERABP crystallized with ligand), EBP-RA (the complex of ERABP and RA) and RA (with the same conformation of RA in the EBP-RA). The results of calculation show that RA has a conformation with the β-ionone ring strething inside and the caboxylate stretching outside. There are 24 residues lining the binding cavity. The conformationn of the binding protein is changed so that the extent of the exposre of the binding cavity increases, which is of advantage to RA binding.