聚乙烯基吡咯烷酮对质粒DNA降解效应的研究

Study on Degradation Effect of Polyvinylpyrrolidone on Plasmid DNA

为评估聚乙烯基吡咯烷酮(Polyvinylpyrrolidone,PVP)的生物可利用性,研究了不同相对分子质量PVP对闭合环状双链质粒DNA pBR322的降解效应.实验结果表明:在常温、非光催化条件下,相对分子质量小的PVP(PVP8000)可引起质粒DNA构象的改变,并且这种效应与反应温度、反应时间及PVP的相对分子质量和浓度相关;另外,在反应体系中加入不同浓度的甲酰胺,PVP 8 000的DNA剪切效应可被显著抑制,结果表明在一定程度上,PVP的表面性质以及DNA构象的稳定性是影响DNA降解的主要因素.

To evaluate the bioavailability of Polyvinylpyrrolidone（PVP）,compared the DNA degradation effect of PVP with different molecular weight on closed circular double-stranded plas-mid pBR322.The results revealed that the lower molecular weight PVP（PVP 8 000） could sig-nificantly degrade the plasmid DNA pBR322 under normal temperature without photoactivation,which was correlated to reaction temperature,reaction time,molecular weight and concentration of PVP.In addition,when different concentrations of formamide were added into the reaction sol-ution,the DNA degradation induced by PVP 8 000 could be dramatically inhibited.These results indicates that the stability of DNA conformation and the surface property of PVP,to certain extent,might be the main factors for the DNA degradation induced by PVP.