Interactions of Ni(<scp>ii</scp>) and Cu(<scp>ii</scp>) ions with the hydrolysis products of the C-terminal -ESHH- motif of histone H2A model peptides. Association of the stability of the complexes formed with the cleavage of the -E–S- bond
作者:Marios Mylonas、John C. Plakatouras、Nick Hadjiliadis
DOI:10.1039/b414679d
日期:——
position 3, the N-terminal amino group and the two amide nitrogens existing between these groups NH2, 2N-, NIm} forming 4N square-planar complexes. While in the case of the CuH(-1)L complex with SHHK- a possible axial coordination of the imidazole ring of His in position 2 was suggested, in the case of the analogous NiH(-1)L complex a completely different interaction of the same ring with metal ions was
我们研究了Ni(II)和Cu(II)离子与合成四肽SHHK-和SAHK-的相互作用,酰胺化阻止了它们的合成,使它们成为H2A组蛋白六肽模型水解肽产物的更真实模型。电位和光谱技术(UV / Vis,CD,NMR和EPR)的结合表明,在pH> 7时,两个四肽都通过3位的His的咪唑环在赤道上配位,存在N端氨基和存在的两个酰胺氮这些基团NH 2,2N-,NIm}之间形成4N正方形-平面络合物。对于具有SHHK-的CuH(-1)L配合物,建议在位置2处His的咪唑环可能发生轴向配位,在类似的NiH(-1)L络合物的情况下,观察到同一环与金属离子的相互作用完全不同。正如预期的那样,由于这些复合物在pH> 7.4时占优势,因此与以前研究的组蛋白H2A C端六肽模型的Ni(II)或Cu(II)辅助水解产生的水解产物具有相同的结构。 。此外,本文提供的竞争图表明,合成四肽SHHK-和SAHK-对Ni(I