基于高分辨质谱及分子对接技术研究适配体与倍氯米松的相互作用

倍氯米松(beclomethasone)是一种有效的糖皮质激素,而倍氯米松适配体是对倍氯米松具有亲和力与特异性的单链DNA分子.目前对两者的相互作用仍不清楚,研究适配体与药物的相互作用对适配体的应用具有一定的意义.本研究采用高分辨傅里叶变换离子回旋共振质谱仪(FT-MS)及分子对接软件计算模拟研究适配体与倍氯米松的相互...

The Interaction between Aptamer and Beclomethasone Based on High Resolution Mass Spectrometry and Molecular Docking

Beclomethasone is an effective glucocorticoid, and beclomethasone-aptamer is a short single-stranded DNA with affinity and specificity to beclomethasone, and the interaction among them is still unclear. The study of the interaction between aptamers and beclomethasone has a certain significance for the application of aptamers. In this study, Fourier transform ion cyclotron resonance mass spectrometer (FT-MS) and molecular docking simulation technology were used to study the interaction between aptamer and beclomethasone. Firstly, under the optimized conditions of high-resolution mass spectrometry parameters, the complex of aptamer and beclomethasone was detected by the negative ion scanning mode with the electrospray ion source. Based on the results of high-resolution mass spectrometry, most of the compounds were -8-valent ions, and their dissociation constant Kd value was 1.01 ± 0.23 μM, as well as the stoichiometric number of the two was 1:1 before saturation; Secondly, molecular docking simulation showed that the stoichiometric number of binding between aptamer and beclomethasone was also 1:1, and the free energy of binding between them was ?24 kcal/M, and they were combined by hydrogen bond force. Finally, Ultra-micro UV was also used to detect the binding between aptamer and beclomethasone through the changes of peak shape before and after the combination, The dissociation constant Kd of the beclomethasone-aptamer complex is 1.67 ± 0.35 μM, which is similar to that of high resolution FT-MS. The detection of FT-MS and molecular docking simulation not only provide the affinity of the aptamer and beclomethasone, but also provide other interaction information such as the ratio of chemical binding stoichiometry between them, which has a certain significance for deepening the application of aptamers.