摘要
The relationship between the yield of thymime-thymine dimer after laser irradiation and physical parameters, such as intensity and pulse number was studied to explore the function of laser irradiation to induce thymine-thymine dimer. A modified high-performance liquid chromatography (HPLC) method has been developed for the determination of thymine-thymine dimer in DNA for. The thymine-thymine dimer was prepared by a photochemical reaction to be used as the standard substance. The HPLC method we proposed is not interfered by other hydrolysate from DNA. The stability and reproducibility are good, and it can determine as little as 4.42×10 -5 μg·mL -1 thymime-thymine dimer. Three levels of laser intensity to irradiate DNA were selected from calf thymine to test the influence of the pulse number. The mechanism of DNA lesion and repair caused by laser irradiation was studied preliminarily.
本文报道了用光化学反应制得的胸腺嘧啶二聚体为标准对照品 ,用改进的RP HPLC方法对DNA激光照射后的水解产物———胸腺嘧啶二聚体进行测定 ,考察了二聚体的产率与照射物理量间的关系 ,发现激光照射的两个物理量———辐射强度和脉冲次数是影响二聚体产率的重要因素 ,但二聚体产率与二者并不成简单的线性关系 ,并初步探讨了其机制 ,认为在反应中胸腺嘧啶和胸腺嘧啶二聚体处于反应动态平衡 ,到达最大平衡点后就表现为激光的修复作用。所建立的HPLC方法不受DNA水解后产生的其他峰干扰 ,稳定性、重现性好 ,最低检测浓度达 4 42× 10 5μg·mL 1 。
