目的 研究射干苷与血浆蛋白的非共价结合特性。方法 采用电喷雾离子阱质谱分别测定射干苷、人血清白蛋白、α₁-酸性糖蛋白及其所形成复合物的相对分子质量。通过结合前后的相对分子质量的变化计算复合物最大化学计量比；通过Scatchard方程拟合计算复合物结合常数K；根据反应温度和热力学常数△H、△S推测复合物间的作用力类型。结果 射干苷与人血清白蛋白、α₁-酸性糖蛋白形成的非共价复合物K分别为1.914×10⁴mol/L和5.893×10⁴mol/L，结合倍数分别为7.8和3.3复合物间的作用力主要为静电引力。结论 电喷雾离子阱质谱法应用于射干苷与蛋白质结合的研究具有灵敏度高、特异性强、分析迅速等优点。

Objective To study the non—covalent binding between the tectoridln(TE)and plasma pro—teins．Methods The molecular weights of TE．human serum albumin(HSA)，α₁-acid glycoprotein(AAG)and the protein—drug complexes were measured by the electrospray ion trap mass spectrometry(ESI—MS)．The maximum stoiehiometrie ratios were obtained according to the molecular weight change of the complexes before and after binding reaction．The binding constants(K)of the complexes were ealculated by the Scatehard equation．The main sorts of binding force of the complexes were deduced according to the relationship between the reaction temperature and the thermodynamic parameters(△H and△5)．Results The K of the complexes were 1．914×10⁴mol/L for TE—HSA and 5，893×10⁴mol/L for TE—AAG，and the number of binding sites were 7．8 and 3．3，respectively．The main sorts of binding force be—tween TE—HSA or TE—AAG were static—electricity gravitation．Conclusion ESI—MS is s good method for studying of the TE—protein non—Covalent binding with some advantages in sensitivity，high—speed，and accuracy

湖北省杰出青年基金资助项目(2002AC004);中药生物技术省重点实验室开放基金项目(040106)