采用等温滴定量热法研究植物凝集素(PHA)作用于20%家兔血红细胞(RBC)的凝集反应过程,以生物热动力学参数表达凝集反应动力学特征.结果表明,PHA与家兔血红细胞凝集反应的平衡常数K为3.24×105 L·mol-1,反应焓变(△r H mΘ)为-238.548 kJ·mol-1,反应自由能(△r GmΘ)为-32.722 kJ·mol-1,反应熵变(△r SmΘ)为-0.664 kJ·mol-1·K-1.反应为放热反应(Q〉0),可自发进行(△G〈0),反应为焓驱动、熵减过程(△H〈0,△S〈0,|△H|〉|T△S|),由化学键合作用、氢键和范德华力推动,反应体系最终处于稳定有序状态.所建立的微量量热法可以客观表征凝集反应的热动力学过程,也为其他抗原抗体类型反应的过程评价方法提供新的技术参考.
Microcalorimetry was adopted to detect the reaction of phytohemagglutinin(PHA) with 20% rabbit red blood cell(RBC),thermokinetics curves and parameters were obtained,so as to evaluate aggluti-nate activity of PHA objectively from reaction process and thermokinetics character aspect.The results showed that thermokinetics parameters of PHA titrated with 20% rabbit RBC were: K(3.24×105 L·mol-1)(-32.722 kJ·mol-1),(-238.548 kJ·mol-1),(-0.664 kJ·mol-1·K-1).The hemoag-glutination is exothermic reaction for Heat0,and it could progress spontaneously for Gibbs free energy was negative(ΔG0),and the reaction was entropy decreasing and driven by enthalpy(ΔH0,ΔS0,|ΔH||TΔS|),the driving force may be chemical bonding force,Van der Waals force and hydrogen bond in-teraction,the reaction system kept in stable and ordered condition after agglutination.In conclusion,the ad-mix ampoule microcalorimetry established in this study could be adopted as an effective technique for sensi-tive,precise,quantitative and consecutive detection of hemoagglutination and other antigen-antibody reac-tions.