中文摘要：

采用表面等离子体共振（SPR）技术研究了肿瘤坏死因子（TNF）与其两种受体的胞外部分即可溶性受体（TNF sRⅠ/Fc Chimera和TNF sRⅡ/Fc Chimera）的相互作用的动力学性质.采用两种方式进行研究：在传感片上氨基偶联固定TNF,测定其与溶液中两种可溶性受体相互作用；在传感片上固定Protein A,通过其与嵌合蛋白TNF sRⅠ/Fc Chimera和TNF sRⅡ/Fc Chimera分子上Fc片段的特异性作用,将可溶性受体“捕获”固定在传感片上,再测定受体与溶液中TNF的相互作用.结果表明,两种固定方式测定的动力学参数相吻合,TNF与其可溶性受体的亲和常数KD大于10-9 mol/L,远高于一般抗体-抗原间的亲和常数（KD=10-5～10-7 mol/L）.

英文摘要：

The kinetic analysis of interaction between tumor necrosis factor （TNF） and its two soluble extracellular receptors （sR I/Fc and sR II/Fc chimera） was carried out by using surface plasmon resonance （SPR） technique. Two immobilization strategies were used. For the first one, TNF was covalently immobilized on the CM5 sensor chip by amine coupling method, and the interaction between TNF and its soluble receptors were analyzed. For the second one, protein A was first covalently immobilized on the CM5 sensor chip by amine coupling method, and TNF sRI/Fc Chimera or TNF sRII/Fc Chimera was subsequently captured on the sensor chip through the specific interaction of their Fc moiety with protein A. The kinetics of immobilized soluble receptors was studied by surface plasmon resonance. The experiment results showed that the kinetic parameters obtained from these two strategies correlated well. The affinity constant ga of TNF with its receptors was around 10-9 mol/L, indicating a higher affinity than that of the antibody-antigen interaction （Ko -- 10-5-10-7 mol/L）