盐酸氯丙嗪对八肋游仆虫中心蛋白C端功能的抑制

通过荧光光谱分析、等温滴定量热(ITC)、圆二色谱(CD)、电泳等技术研究了盐酸氯丙嗪(CPZ)和八肋游仆虫中心蛋白C端(apoC-EoCen)的结合以及CPZ对蛋白功能的影响。结果表明,在室温下10 mmol·L^-1 Hepes溶液(pH=7.4)中,CPZ与apoC-EoCen以物质的量之比为1∶1结合,条件结合常数约为104L·mol^-1。CPZ的结合导致蛋白质的二级结构发生改变,α螺旋含量减小;对金属离子诱导中心蛋白的聚集产生了抑制作用,Tb3+敏化荧光强度也降低;阻碍了中心蛋白与着色性病干皮病C组蛋白(XPC)的结合;且影响了apoC-EoCen类核酸酶活性,导致蛋白对pBR322 DNA的切割能力下降;抑制了蛋白质的磷酸化。综合实验结果表明盐酸氯丙嗪是中心蛋白的生物功能阻断剂,对中心蛋白的功能具有良好的调控作用。

Inhibition of Functions for C-Terminal Domain of Euplotes Octocarinatus Centrin by Chlorpromazine Hydrochloride

The binding of chlorpromazine(CPZ)to the C-terminal domain of Euplotes octocarinatus centrin(apoCEoCen)and the effect of CPZ on the protein function were studied by fluorescence spectra,isothermal titration calorimetry(ITC),circular dichroism(CD)and electrophoresis.The results illustrated that in 10 mmol·L^-1 Hepes solution(pH=7.4)at room temperature,CPZ and apoC-EoCen were combined with a molar ratio of 1∶1,in addition,the conditional binding constant was about 104 L·mol^-1.The combination of CPZ leads to changes in the secondary structure of the protein,and the content ofα-helix is reduced.It inhibits the aggregation of centrin induced by metal ions and reduces the fluorescence intensity of Tb3+sensitization.CPZ suppresses the binding of centrin to xeroderma pigmentosum protein(XPC).The activity of apoC-EoCen nuclease is affected,which results in the decreased capability of protein to cut pBR322 DNA.The results indicate that chlorpromazine hydrochloride is a biological function antagonist of centrin,and it has a good regulatory effect on the function of centrin.