共查询到3条相似文献,搜索用时 0 毫秒
1.
Assessment of DNA Binding to Human Rad51 Protein by using Quartz Crystal Microbalance and Atomic Force Microscopy: Effects of ADP and BRC4‐28 Peptide Inhibitor 下载免费PDF全文
Dr. Charles Esnault Dr. Axelle Renodon‐Cornière Dr. Masayuki Takahashi Dr. Nathalie Casse Dr. Nicolas Delorme Prof. Guy Louarn Prof. Fabrice Fleury Prof. Jean‐François Pilard Prof. Benoît Chénais 《Chemphyschem》2014,15(17):3753-3760
The interaction of human Rad51 protein (HsRad51) with single‐stranded deoxyribonucleic acid (ssDNA) was investigated by using quartz crystal microbalance (QCM) monitoring and atomic force microscopy (AFM) visualization. Gold surfaces for QCM and AFM were modified by electrografting of the in situ generated aryldiazonium salt from the sulfanilic acid to obtain the organic layer Au–ArSO3H. The Au–ArSO3H layer was activated by using a solution of PCl5 in CH2Cl2 to give a Au–ArSO2Cl layer. The modified surface was then used to immobilize long ssDNA molecules. The results obtained showed that the presence of adenosine diphosphate promotes the protein autoassociation rather than nucleation around DNA. In addition, when the BRC4‐28 peptide inhibitor was used, both QCM and AFM confirmed the inhibitory effect of BRC4‐28 toward HsRad51 autoassociation. Altogether these results show the suitability of this modified surface to investigate the kinetics and structure of DNA–protein interactions and for the screening of inhibitors. 相似文献
2.
通过表面引发的原子转移自由基聚合在硅片表面制备了聚(N-异丙基丙烯酰胺)(PNIPAAm)聚合物刷。用原子力显微镜(AFM)分别研究了PNIPAAm的接枝动力学、温度和溶剂性质对厚度的影响以及PNIPAAm链与原子力针尖间的粘附力。结果表明,PNIPAAm链在硅片表面的生长具有很好的可控性。常温下厚度为33nm的PNIPAAm膜在水溶液中的增加到82.4nm;而在甲醇/水(v/v,1:1)溶液中,PNIPAAm分子链处于坍塌收缩状态,厚度降低为45nm;在55℃下干燥所得厚度则仅为22nm。力-距离测量结果表明,在溶液中,PNIPAAm链与原子力针尖之间的粘附力远小于在干态下的粘附力。用石英晶体微天平(QCM-D)对PNIPAAm的可逆相转变进行了研究,结果表明PNIPAAm分子链随温度变化的构象转变是发生在30-34℃之间的连续过程。 相似文献