Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
J Biomol Struct Dyn. 2020 Feb;38(2):364-381. doi: 10.1080/07391102.2019.1574240. Epub 2019 Feb 17.
The binding of small molecules with histone-DNA complexes can cause an interference in vital cellular processes such as cell division and the growth of cancerous cells that results in apoptosis. It is significant to study the interaction of small molecules with histone-DNA complex for the purpose of better understanding their mechanism of action, as well as designing novel and more effective drug compounds. The fluorescence quenching of ct-DNA upon interaction with Berberine has determined the binding of Berberine to ct-DNA with = 9.46 × 10 M. value of ct-DNA-Berberine in the presence of H1 has been observed to be 3.10 × 10 M, indicating that the H1 has caused a reduction in the binding affinity of Berberine to ct-DNA. In the competitive emission spectrum, ethidium bromide (EB) and acridine orange (AO) have been examined as intercalators through the addition of Berberine to ct-DNA complexes, which includes ctDNA-EB and ctDNA-AO. Although in the presence of histone H1 , we have observed signs of competition through the induced changes within the emission spectra, yet there has been apparently no competition between the ligands and probes. The viscosity results have confirmed the different behaviors of interaction between ctDNA and Berberine throughout the binary and ternary systems. We have figured out the IC50 and viability percent values at three different time durations of interaction between Berberine and MCF7 cell line. The molecular experiments have been completed by achieving the results of MTT assay, which have been confirmed to be in good agreement with molecular modeling studies.Communicated by Ramaswamy H. Sarma.
小分子与组蛋白-DNA 复合物的结合会干扰细胞分裂等重要的细胞过程，以及导致癌细胞的生长，从而引发细胞凋亡。研究小分子与组蛋白-DNA 复合物的相互作用对于更好地理解其作用机制以及设计新型、更有效的药物化合物具有重要意义。小檗碱与 ct-DNA 相互作用导致 ct-DNA 的荧光猝灭，确定了小檗碱与 ct-DNA 的结合常数为 9.46×10 M。在 H1 存在下，ct-DNA-小檗碱的值为 3.10×10 M，表明 H1 降低了小檗碱与 ct-DNA 的结合亲和力。在竞争发射光谱中，通过向 ct-DNA 复合物（包括 ctDNA-EB 和 ctDNA-AO）中添加小檗碱，研究了溴化乙锭 (EB) 和吖啶橙 (AO) 作为嵌入剂。尽管在存在组蛋白 H1 的情况下，我们通过发射光谱中的诱导变化观察到竞争的迹象，但配体和探针之间显然没有竞争。粘度结果证实了 ctDNA 和小檗碱在二元和三元体系中相互作用的不同行为。我们已经确定了小檗碱与 MCF7 细胞系相互作用三个不同时间间隔的 IC50 和存活百分比值。通过完成 MTT 测定实验，获得了分子实验的结果，这与分子建模研究结果非常吻合。通讯作者为 Ramaswamy H. Sarma。
