基于等温滴定量热法表征的红细胞凝集反应热动力学特性研究

Investigation on the Thermokinetics Process of Hemoagglutination by Isothermal Titration Calorimetry

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.