纳米材料对DNA热变性行为的影响

Influence of Nanomaterials on Heat-Induced Denaturation Process of DNA

在基因操作过程中经常需要对脱氧核糖核酸(DNA)进行高温处理,如在聚合酶链式反应PCR操作中就需要对模板DNA进行升降温的操作,因此,DNA的热变性行为是关系到一些基因操作效率高低的关键.琼脂糖凝胶电泳实验显示,1,972,bp的短链λDNA高温处理后在1,000,bp左右处出现额外一条下带,而且此条带经过37,℃处理数小时即可恢复到1,972,bp,不像48,000,bp长链λDNA那样在高温处理后出现弥散现象.另外,显著添加不同的纳米材料对下带出现的温度有明显的影响,意味着添加适量纳米材料可以改变DNA分子结构对温度的敏感性.所发现的下带可能具有尚未报道过的特殊结构.

In the process of genetic manipulations,DNA is often treated by high temperatures,as in the polymerase chain reaction （PCR）where DNA is subjected to big temperature fluctuations. Therefore the heat-induced denaturation process is closely related with efficiencies of DNA manipulations. When a 1 972 bp short k DNA fragment was treated by agarose gel electrophoresis at high temperature,a lower band with the size of about 1 000 bp repeatedly appeared;Moreover,the lower band can be resumed to 1 972 bp after a few hours incubation at 37℃ ,while the 48 000 bp long k DNA only demonstrated dispersion after the treatment of high temperature. In this study,it is found that different nanomaterials differentially influenced the heat-induced denaturation process of DNA by changing the behavior of the lower band that might possess a specific structure never reported. The results suggest that nanomaterials change the temperature sensitivity of DNA structure.