为探讨DNA凝聚的性质和机制, 探究了不同浓度的精胺、 亚精胺和三氯六氨合钴对小牛胸腺DNA紫外吸收的影响。 精胺、 亚精胺与DNA相互作用在紫外光谱上具有相似特征, 随着它们浓度的增加紫外光谱在260 nm处都有先增色, 后减色, 再增色的趋势; 随着三氯六氨合钴浓度的升高紫外光谱出现先减色, 后增色。 精胺、 亚精胺和三氯六氨合钴与DNA相互作用均能使DNA凝聚, 但作用方式有所不同。 三氯六氨合钴较之精胺、 亚精胺与DNA相互作用更为敏感。 多胺紫外光谱分析结果与最近单分子实验结果吻合。

In order to explore the property and mechanism of DNA condensation, the authors studies the effect of different concentrations of spermine(SPM), spermidine(SPD) and hexamminecobalt(Ⅲ) chloride on the ultraviolet(UV) absorption value of calf thymus DNA by UV spectrophotometer from the macro. The results showed that SPD and SPM interaction with the DNA had the similar characteristics in UV spectrum. The UV absorption value of calf thymus DNA at 260 nm appeared increased-decreased-increased with the increasing the concentration of SPD and SPM. The value of hexamminecobalt(Ⅲ) chloride system showed decreased and then increased, suggesting that SPM, SPD and hexamminecobalt(Ⅲ) chloride could make DNA condense, but in different ways. Relatively, hexamminecobalt(Ⅲ) chloride was more sensitive than SPD and SPM. The result of UV spectral analysis coincided with recent single-molecule experimental results.