摘要
通过测定不同浓度Hg2+和Cu2+与酸性磷酸酶(APase)及量子点标记酸性磷酸酶(QD-APase)体系在不同温度下发生相互作用后的荧光变化,计算热力学常数,检测Hg2+和Cu2+对APase及QD-APase活性等手段,研究了Hg2+和Cu2+与APase及QD-APase之间的相互作用效应.结果表明:Hg2+、Cu2+均能对APase及QD-APase的构象与活性产生影响,但首先是通过对APase和QD-APase的结构造成影响,进而才会对其活性产生抑制效应,且Hg2+对APase和QD-APase的构象及活性的影响与约10倍剂量的Cu2+相当.Hg2+、Cu2+与QDAPase体系发生结合反应的能力强于与APase的结合,前者的结合反应是由焓熵共同驱动,而后者的结合主要是由熵驱动.根据研究结果可以设计出荧光性能优异且具有生物活性的酶探针,在生物标记及荧光分析法检测重金属离子对酶的作用效应方面具有良好的应用前景.
In this paper,the fluorescence of the system was measured under different temperatures with various concentrations of Hg^2＋ and Cu^2＋ interacting with Apase and QD-APase.Thermodynamic constants of the Cu^2＋ and Hg^2＋ binding to APase and QDAPase were calculated and the effect of metal ions on the enzymatic activity of APase with or without QD labeling was determined.By these means,the interaction between Hg^2＋,Cu^2＋,and acidic phosphatase with or without QD labeling is studied.The results showed that both Cu^2＋ and Hg^2＋ showed an influence on the configuration of the APase with or without QD-labeling before the enzymatic activity of the enzymatic system was affected.Dose effect of Hg^2＋ on the system was 10 times higher than that of Cu^2＋.The binding affinity of the metal ions with QD-APase complex was much higher than with APase alone.The former binding reaction was powered by entropy and enthalpy change whereas the latter was powered by entropy change alone.Enzymatic probe of excellent fluorescent features and biological activities can be designed based on the result of the study,which was very promising in its application in bio-labeling and detection and measurement of the effect of heavy metal ions on enzymes by fluorescence activity.
出处
《华中师范大学学报（自然科学版）》
CAS
北大核心
2014年第4期559-564,共6页
Journal of Central China Normal University：Natural Sciences
基金
国家863计划(2007AA06Z418)
武汉市卫生局公共卫生科研项目(WG08A02)
