酪氨酸四肽与ct-DNA的相互作用

摘要

A model peptide,Tyr-Tyr-Tyr-Tyr(YYYY),was synthesized by Fmoc solid-phase methods,purified and separated by reverse phase high performance liquid chromatography (RP-HPLC),and characterized by ESI-MS analysis.The interaction of peptide with calf thymus DNA (ct-DNA) was investigated by UV-Vis absorption spectra,circular dichroism (CD) and fluorescence spectra.The results showed that,with the increase of peptide concentration,there were a hyperchromic effect on UV spectra,a remarkable fluorescence quenching and a red shift of CD.It is possible that Tyr-Tyr-Tyr-Tyr and Tyr might interact with ct-DNA via the groove binding mode.The interaction between Tyr-Tyr-Tyr-Tyr and ct-DNA,compared with that between Tyr and ct-DNA,is more stronger.%采用Fmoc固相合成法合成了酪氨酸四肽(YYYY),经液相色谱-高效液相色谱(RP-HPLC)纯化,并用电喷雾质谱(ESI-MS)表征后,得到纯度大于90％的四肽,利用紫外光谱、圆二色光谱和荧光光谱研究了肽YYYY与ct-DNA的相互作用.结果表明,随着肽浓度的增加,ct-DNA的紫外吸收产生明显的增色效应,荧光猝灭显著,圆二色光谱发生红移.研究推测酪氨酸四肽以沟槽方式与ct-DNA发生相互作用,且酪氨酸四肽与ct-DNA的作用强于酪氨酸.