抗艾滋病药物司他夫定与血液蛋白相互作用的研究

研究药物和血液中载体蛋白的相互作用对阐明药物在体内的转运、分布、代谢和药效等具有重要意义。运用稳态荧光、紫外-可见吸收光谱、动力学瞬态发射光谱和循环伏安法研究了抗艾滋病(HIV)药物司他夫定(stavudine，D4T)对人血清白蛋白(HSA)、牛血清白蛋白(BSA)和血红蛋白(Hb)三种血液蛋白的荧光猝灭机制，均为静态猝灭；得出不同温度(300 K，310 K，320 K)下D4T和载体的结合常数K_a(K_a的大小顺序为Hb＞HSA＞BSA)和结合位点数n(n均为1)；分析二者结合过程的热力参数ΔH，ΔS和ΔG，三种血液蛋白均为ΔG＞0，ΔH＞0，说明D4T和载体的结合是一种自发的放热过程，同时由ΔH＜0，ΔS＜0，推测出D4T与HSA，BSA和Hb之间的结合力都为氢键和范德华力；根据Frster非辐射能量转移理论(FRET)分析了供体(蛋白)和受体(D4T)之间发生能量转移的可能性并计算了结合距离R₀和r，其中r＜7 nm且0.5R₀＜r＜1.5R₀，表明从HSA，BSA和Hb到D4T之间发生能量转移的可能性很大。同时利用同步荧光，三维荧光和圆二色谱法得出，D4T与载体结合时对载体(HSA，BSA和Hb)的二级结构无影响，且三级构象变化不大。通过本文实验可知，HSA，BSA和Hb三种血液蛋白均可作为运输D4T到靶位置的良好载体蛋白，这些结果为更深入研究D4T药物分子设计和抗HIV作用的应用提供有利的实验依据。

Study on the Interaction Between the Anti-HIV Drug Stavudine and the Blood Protein

Studies on interactions between drugs and carrier proteins in blood is important for elucidating the transport,distribu-tion,metabolism and efficacy of drugs in vivo.In this report,the fluorescence quenching mechanism of anti-HIV drug stavudine (D4T)with human serum albumin (HSA),bovine serum albumin (BSA)and hemoglobin (Hb)were determined with investi-gatingsteady state fluorescence,UV-Vis absorption spectra ,kinetic transient emission spectra and cyclic voltammetry.The binding constant K a (the size of the order of K a is Hb> HSA>BSA)and binding sites n (n = 1 )of D4T binding with carriers were obtained in different temperatures (300,310 and 320 K).Analysis of thermodynamic parameters ΔH ,ΔS and ΔG of bind-ing process,we can know that these three types of blood proteins are the ΔG<0 and ΔH <0,illustrating that combination of d4T and carriersare a spontaneous exothermic process,also by the ΔH <0 and ΔS <0,we can deduce that the binding force be-tween D4T and HSA,BSA and Hb are hydrogen bonds and van der Waals force.The possibility of energy transfer and binding distance (R 0 and r)between donor (proteins)and acceptor (D4T)were obtained according to non-radiative energy transfer theo-ry (FRET).The r is less than 7 nm and 0.5R 0