The interaction of calf thymus DNA (ct DNA) with anastrozole, which is acknowledged as an antineoplastic drug, has been enquired into in the absence and presence of histone H1, through the means of absorbance, fluorescence, circular dichroism spectroscopy, viscosity, thermal melting, and molecular modeling techniques. In addition, the effects of anastrozole on MCF 7 cell line have been thoroughly investigated. Fluorescence spectroscopy results have indicated that quenching mechanism of ct DNA-anastrozole are known as static quenching procedures, since the Stern-Volmer quenching constant (K_SV) seems to face a decrease as the temperature is enhanced; this is a significant evidence for intercalative binding mode of anastrozole with ct DNA. Regarding the ternary system in the presence of H1, the constant of Stern-Volmer quenching was increased as the temperature was heightened. The thermodynamic parameters suggested that the binding could be characterized as exothermic by negative and positive enthalpy and entropy changes in both binary and ternary systems, respectively. It is vital to mention that hydrogen bonds and hydrophobic contributions play significant roles in anastrozole association to ct DNA in the absence and presence of H1. In accordance to the absorption spectroscopy and melting temperature curve outcomes, the binding mode of anastrozole with ct DNA in absence and presence of H1 was indicative of intercalative and nonintercalative bindings, respectively. The viscosity results as binary and ternary systems, which have been elucidated from a sensitive viscometer, have confirmed the fluorescence spectroscopy determinations. The intercalation of anastrozole to ct DNA seemed to be significantly related to an induced reduction in MCF-7 cell proliferation. The molecular modeling results have suggested that anastrozole could bind to H1 in ct DNA-H1 complex in ternary systems, which supports the conclusions that have been obtained from experimental data.

中文翻译：

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测定小牛胸腺 DNA 与阿那曲唑在组蛋白 H1 存在下的相互作用行为：MCF-7 细胞系研究的光谱学和细胞活力

小牛胸腺 DNA (ct DNA) 与公认的抗肿瘤药物阿那曲唑的相互作用已通过吸光度、荧光、圆二色光谱、粘度、热熔解等手段在组蛋白 H1 不存在和存在的情况下进行了研究和分子建模技术。此外，阿那曲唑对 MCF 7 细胞系的影响已得到彻底研究。荧光光谱结果表明ct DNA-阿那曲唑的猝灭机制被称为静态猝灭程序，因为Stern-Volmer猝灭常数（K _SV) 似乎随着温度的升高而减少；这是阿那曲唑与 ct DNA 的嵌入结合模式的重要证据。对于存在 H1 的三元体系，Stern-Volmer 猝灭常数随着温度的升高而增加。热力学参数表明结合可以分别通过二元和三元系统中的负和正焓和熵变化表征为放热。值得一提的是，在 H1 不存在和存在的情况下，氢键和疏水作用在阿那曲唑与 ct DNA 的结合中起着重要作用。根据吸收光谱和熔解温度曲线结果，在不存在和存在 H1 的情况下，阿那曲唑与 ct DNA 的结合模式分别指示嵌入和非嵌入结合。作为二元和三元系统的粘度结果，已经从灵敏的粘度计阐明，已经证实了荧光光谱测定。阿那曲唑嵌入 ct DNA 似乎与 MCF-7 细胞增殖的诱导减少显着相关。分子建模结果表明，阿那曲唑可以在三元系统中与ct DNA-H1复合物中的H1结合，这支持了从实验数据中得出的结论。阿那曲唑嵌入 ct DNA 似乎与 MCF-7 细胞增殖的诱导减少显着相关。分子建模结果表明，阿那曲唑可以在三元系统中与ct DNA-H1复合物中的H1结合，这支持了从实验数据中得出的结论。阿那曲唑嵌入 ct DNA 似乎与 MCF-7 细胞增殖的诱导减少显着相关。分子建模结果表明，阿那曲唑可以在三元系统中与ct DNA-H1复合物中的H1结合，这支持了从实验数据中得出的结论。