【摘要】 本文研究了光敏氧化前后甲素与DNA的结合以及这种结合对DNA-EB复合物荧光强度、DNA融解温度和圆二色谱的影响。利用Sephadex G-150凝胶过滤和同位素技术分离甲素-DNA复合物,测得光照前后甲素与DNA的结合率分别为15.2％和27.8％。荧光测定和琼脂糖凝胶电泳结果显示:甲素可阻碍DNA-EB复合物的形成、使DNA-EB复合物的荧光强度减弱,光照甲素对DNA-EB复合物的荧光淬灭作用较未光照者为强。甲素敏化DNA光氧化后的荧光淬灭、DNA融解温度降低和CD谱变化提示:甲素敏化DNA光氧化涉及碱基破坏及DNA双螺旋结构改变。更多还原

【Abstract】 The binding of Hypocrellin A(HA) to DNA prior to and after irradiation and its effects on the fluorescence of DNA-EB complex and changes of temperature-dependent UV absorption and circular dichroism spectrum of DNA were studied in this work. The H-HA-DNA complex was separated from free 3H-HA by Sephadex G-150 gel filtration. The binding ratios of HA to DNA. prior to and post irradiation were 15.2% and 27.8% respectively. The results in fluorescence determination and agarose gel electrophoresis showed that HA inhibited the formation of DNA-EB complex; the quenching of fluorescence of DNA-EB complex by irradiated HA was stronger than that by non-irradiated HA.The decrease of temperature-dependent UV absorption of DNA and the changes in circular dichroism spectra of DNA suggested DNA destruction in photooxidation of DNA sensitized by HA.更多还原