等温滴定量热法研究镉离子与GMP的亲合机理  

The Affinity Mechanism Between Cadmium Ion and GMP Was Studied by Isothermal Titration Calorimetry

作　　者：于劲松[1] 黄煦 任方圆 黎瑛婕 李朝霞 阿丽娅 吕欣欣 曹慧[1] 袁敏[1] 叶泰[1] 吴秀秀 郝丽玲 徐斐[1] YU Jinsong;HUANG Xu;REN Fangyuan;LI Yingjie;LI Zhaoxia;A·Kepen Ye Liya;LV Xinxin;CAOHui;YUAN Min;YE Tai;WU Xiuxiu;HAO Liing;XU Fei(School of Health Science and Engineering,Shanghai Engineering Research Center for Food Rapid Detection,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学健康科学与工程学院/上海食品快速检测工程技术研究中心,上海200093

出　　处：《工业微生物》2024年第1期184-190,共7页Industrial Microbiology

基　　金：国家自然科学基金项目(32072312)。

摘　　要：利用等温滴定量热法研究镉离子与鸟嘌呤核糖核苷酸(GMP)的亲合过程,重点分析不同比例的镉离子和GMP结合时的异同,实验结果显示:(1)镉离子和GMP的浓度比不同会对二者的结合过程产生显著影响,在低浓度比下,反应为焓驱动的放热反应;在高浓度比下,反应为吸热反应。从镉离子和GMP浓度比为20∶1时的ITC滴定曲线和OneSite模型拟合结果可知,镉离子和GMP是接近并按照1∶1的比例结合的,二者的亲合力K值为1.21E 4±2.26E 3。(2)推测GMP与镉离子有两个结合位点,一个为放热结合位点,一个为吸热结合位点,在低浓度比下,只有放热结合位点发生结合。当浓度比到达一定值后,会激活吸热结合位点,同时发生吸热结合和放热结合。因为吸热结合位点的结合能力更强,最终可能呈现为吸热反应。(3)通过反滴法和正滴法的比较,同一浓度下,不同的滴加方式也会对结合结果造成较大的影响。该研究所采用的方法可以很好地从宏观的热力学角度分析金属镉离子与GMP的亲合机理,以期为后续镉离子印迹物制备过程中功能单体的筛选提供重要的试验基础和理论指导。The affinity process of cadmium ion and guanine ribonucleotide(GMP)was studied by isothermal titration calorimetry,focusing on the similarities and differences between different proportions of cadmium ion and GMP.The experimental results showed that:(1)the different concentration ratio of cadmium ion and GMP had a significant effect on the binding process,and the reaction was enthalpy driven exothermic reaction at low concentration ratio.At high concentration ratio,the reaction was endothermic.According to the ITC curve and OneSite model fitting results when the concentration ratio of cadmium ion to GMP was 20∶1,cadmium ion and GMP were close to the binding ratio of 1∶1,and the affinity K value was 1.21E 4±2.26E 3.(2)It was speculated that GMP and cadmium ion had two binding sites,one was exothermic binding site and the other was endothermic binding site.At low concentration ratio,only exothermic binding site occurred.When the concentration ratio reached a certain value,endothermic binding sites will be activated,and endothermic and exothermic binding will occur at the same time.Because the endothermic binding site was more powerful,the reaction may become endothermic.(3)Through the comparison of the reverse drop method and the positive drop method,under the same concentration,different drop adding methods will also have a greater impact on the combined results.The method adopted in this study can well analyze the affinity mechanism of metal cadmium ion and GMP from the macroscopic thermodynamic point of view,and the research results provided an important experimental basis and theoretical guidance for the screening of functional monomers in the subsequent preparation of cadmium ion imprinting.

关 键 词：等温滴定量热法 镉离子 功能单体 

分 类 号：X830[环境科学与工程—环境工程] O657.99[理学—分析化学]