Interaction of Cu(II)-Arg-Gly-His-Xaa metallopeptides with DNA: effect of C-terminal residues, Leu and Glu.
Interaction of Cu(II)-Arg-Gly-His-Xaa metallopeptides with DNA: effect of C-terminal residues, Leu and Glu.
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DOI：
10.1016/s0162-0134(02)00619-0
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发表时间：
2003-01
影响因子：
3.9
通讯作者：
R. Nagane;T. Koshigoe;M. Chikira
中科院分区：
文献类型：
--
作者：
R. Nagane;T. Koshigoe;M. Chikira
通过 DNA 纤维 EPR 光谱、ESI-MS 光谱和琼脂糖凝胶电泳研究了 Cu(II)–Arg–Gly–His–Xaa 金属肽与 DNA（其中 Xaa 是 l-Leu 或 l-Glu）的相互作用。 Cu(II)–Arg–Gly–His–Leu 的 g// 轴与 DNA 纤维轴之间的平均角度从室温下的 45° 增加到 -150°C 下的 90°。 Cu(II)-Arg-Gly-His-Glu 复合物在 DNA 上部分解离到几个物种。主要物种的 g// 值 (2.341) 小于观察到的与 DNA 结合的游离 Cu(II) 离子的 g// 值 (2.377)。这表明 Cu(II) 离子被肽转移到游离 Cu(II) 离子难以到达的 DNA 位点。 Cu(II) 肽复合物和寡脱氧核苷酸混合物的 ESI-MS 谱图[d(CGCGTATACGCG)]表明，Cu(II) 肽复合物和双链寡脱氧核苷酸的最大结合化学计量分别为：Cu(II)–Arg–Gly–His–Leu 为 3:1，Cu(II)–Arg–Gly–His–Glu 为 2:1。 Cu(II)–Arg–Gly–His–Glu 将超螺旋 DNA 完全转化为带切口的环状形式，而当添加过量配体时，切割活性显着降低。在存在过量肽的情况下，Cu(II)-Arg-Gly-His-Leu 的切口 DNA 形成率分别为 64%，Cu(II)-Arg-Gly-His-Glu 的切口 DNA 形成率分别为 15%。 Cu(II)-Arg-Gly-His-Glu 上的负电荷降低了复合物对 DNA 的亲和力，增强了结合的特异性。
The interactions of Cu(II)–Arg–Gly–His–Xaa metallopeptides with DNA (where Xaa is l-Leu or l-Glu) were investigated by DNA-fiber EPR spectroscopy, ESI-MS spectrometry, and agarose gel electrophoresis. The average angle between the g// axis of Cu(II)–Arg–Gly–His–Leu and the DNA-fiber axis increased from 45° at room temperature to 90° at −150°C. The Cu(II)–Arg–Gly–His–Glu complex partly dissociated on DNA to several species. The g//value (2.341) of the main species was smaller than that (2.377) observed for free Cu(II) ion bound to DNA. This indicated that the Cu(II) ion was transferred by the peptide to a DNA site where the free Cu(II) ion can hardly reach. ESI-MS spectra of a mixture of the Cu(II) peptide complex and the oligodeoxynucleotide, [d(CGCGTATACGCG)], suggested that the maximum binding stoichiometries of Cu(II) peptide complexes and double stranded oligodeoxynucleotides were 3:1 for Cu(II)–Arg–Gly–His–Leu and 2:1 for Cu(II)–Arg–Gly–His–Glu, respectively. Cu(II)–Arg–Gly–His–Glu completely converted the supercoiled DNA to the nicked-circular form, whereas the cleavage activity was considerably reduced when excess ligand was added. In the presence of excess peptide, nicked DNA formation ratios were 64% for Cu(II)–Arg–Gly–His–Leu and 15% for Cu(II)–Arg–Gly–His–Glu, respectively. The negative charge on Cu(II)–Arg–Gly–His–Glu reduced the affinity of the complex for DNA and enhanced the specificity of the binding.