蚂蚁提取液对DNA-蛋白质交联修复能力的研究

Study on the Repair Ability of Ant Extract on DNA-Protein Crosslinks

目的探讨蚂蚁提取液(ant extract,AE)对DNA-蛋白质交联(DPC)的修复能力。方法以甲醛为染毒液,预处理小牛胸腺DNA和卵清蛋白混合液,使之形成DPC,再用不同浓度的AE处理,最后采用SDS-KCl沉淀法来检测不同处理组的DPC修复情况。结果当甲醛染毒浓度为0.544mol/L时,10μg/ml的小牛胸腺DNA和10μg/ml的卵清蛋白DNA-蛋白质交联程度最高;制备2%的AE时,选择pH 7.6的磷酸氢二钠-磷酸二氢钠缓冲液作为组织匀浆液,AE具有最强的DPC修复能力,且用pH 3.6的柠檬酸-柠檬酸三钠缓冲液制备的AE也具有部分DPC修复能力;0.002%、0.02%、0.2%和2%的AE具有一定的DPC修复能力,且存在明显的浓度-效应关系。结论本研究确定了蚂蚁提取液制备过程中缓冲液的最佳pH值,并证明了蚂蚁提取液具有一定的DPC修复能力。

Objective To investigate the repair capacity of ant extract （AE） on the DNA - protein crosslinks （DPC）. Methods Calf thymus DNA and ovalbumin mixture with formaldehyde solution were pretreated and they were made to form DPC. Then different con- centrations of AE were used for DPC repair, and finally SDS - KCI precipitation method was used to detect DPC repair capacity of different AE groups. Results When the formaldehyde exposure concentration was at 0. 544mol/L for treating the mixture of 10μg/ml calf thymus DNA and 10μg/ml ovalbumin, the DNA -protein crosslink was up to the highest level. When 2% AE solution was made with pH = 7.6 disodium phosphate - sodium dihydrogen phosphate buffer, the AE had the highest capacity to repair the DPC, and when 2% AE solution was made with pH = 3.6 citric acid -sodium citrate buffer, the AE also had some capacity to repair the DPC. Along with AE concentra- tion increasing, （0. 002% , 0.02% , 0. 2% and 2% ） the DPC repair capacity of AE solution increased, and an obvious dose -response effect between AE concentration and DPC repair capacity of AE can be found. Conclusion This paper presents the optimal buffer pH for making ant extract （ pH = 7.6） , and finds the ant extract has a certain DPC repair capacity.