Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, Uttar Pradesh, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2013 May;108:151-8. doi: 10.1016/j.saa.2013.01.059. Epub 2013 Feb 1.
New tetrapeptide complexes Cu(II)·Ala-Pro-Ala-Pro (1) and Zn(II)·Ala-Pro-Ala-Pro (2) were synthesized from the reaction of tetrapeptide, Ala-Pro-Ala-Pro and CuCl2/ZnCl2 and were thoroughly characterized by elemental analysis, IR,(1)H and (13)C NMR (in case of 2), ESI-MS, UV and molar conductance measurements. The solution stability study was carried out employing UV-vis absorption titrations over a broad range of pH which suggested the stability of the complexes in solution. In vitro interaction of complexes 1 and 2 with CT-DNA was studied employing UV-vis, fluorescence, circular dichroic and viscometry studies. To throw insight into molecular binding event at the target site, UV-vis titrations of 1 and 2 with mononucleotides of interest viz.; 5'-GMP and 5'-TMP were carried out. Cleavage activity of the complexes with pBR322 plasmid DNA was evaluated by agarose gel electrophoresis and, the electrophoresis pattern demonstrated that both the complexes 1 and 2 are efficient cleavage agents. Further, the Cu(II) complex displayed efficient oxidative cleavage of supercoiled DNA while various reactive oxygen species are responsible for the cleavage in Zn(II) complex.
新的四肽配合物 Cu(II)·Ala-Pro-Ala-Pro (1) 和 Zn(II)·Ala-Pro-Ala-Pro (2) 是由四肽 Ala-Pro-Ala-Pro 与 CuCl2/ZnCl2 反应合成的，并通过元素分析、IR、(1)H 和 (13)C NMR（对于 2）、ESI-MS、UV 和摩尔电导率测量进行了彻底的表征。通过在宽 pH 范围内进行 UV-vis 吸收滴定进行溶液稳定性研究，表明配合物在溶液中的稳定性。采用 UV-vis、荧光、圆二色性和粘度研究研究了配合物 1 和 2 与 CT-DNA 的体外相互作用。为了深入了解靶位点的分子结合事件，进行了与感兴趣的单核苷酸（即 5'-GMP 和 5'-TMP）的 1 和 2 的 UV-vis 滴定。通过琼脂糖凝胶电泳评估了配合物与 pBR322 质粒 DNA 的切割活性，电泳图谱表明两种配合物 1 和 2 都是有效的切割剂。此外，Cu(II) 配合物显示出有效氧化切割超螺旋 DNA，而各种活性氧物种负责 Zn(II) 配合物的切割。
