The DNA-bound orientation of Cu(II)-Xaa-Gly-His metallopeptides.
The DNA-bound orientation of Cu(II)-Xaa-Gly-His metallopeptides.
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Cu(II)-Xaa-Gly-His 金属肽的 DNA 结合方向。
DOI：
10.1016/s0162-0134(00)00129-x
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发表时间：
2001
影响因子：
3.9
通讯作者：
Long,EC
中科院分区：
文献类型：
--
作者：
Nagane,R;Koshigoe,T;Chikira,M;Long,EC
利用DNA纤维EPR光谱和分子模型研究了Cu（II）·Xaa-Gly-l- his金属肽（其中Xaa是Gly， l-Lys或l-Arg）的DNA结合取向。观察和计算的EPR谱表明，三肽1:1 Cu（II）配合物的g//轴与DNA纤维轴倾斜约50°。这些结果表明，这些配合物在DNA小凹槽中是立体定向的。虽然n端氨基酸残基的侧链不影响DNA结合复合物的取向，但它有助于它们在DNA存在下的稳定性；Gly-Gly-l-His的Cu（II）配合物比l-Lys-Gly-l-His和l-Arg-Gly-l-His更广泛地解离成水合Cu（II）离子。带正电荷的赖氨酸或精氨酸残基与带负电荷的DNA磷酸二酯主链之间的离子相互作用可能导致这些配合物与DNA小槽结合时解离减少。
The DNA-bound orientations of Cu(II)·Xaa-Gly-l-His metallopeptides (where Xaa is Gly, l-Lys or l-Arg) were investigated by DNA fiber EPR spectroscopy and molecular modeling. Observed and calculated EPR spectra indicated that the g//axes of 1:1 Cu(II) complexes of the tripeptides tilted about 50° from the DNA fiber axis. These results suggest that the complexes are stereospecifically oriented in the DNA minor groove. Although the side chain of the N-terminal amino acid residue did not affect the orientation of the DNA-bound complexes, it contributed to their stability in the presence of DNA; the Cu(II) complex of Gly-Gly-l-His was found to dissociate to hydrated Cu(II) ion more extensively than the respective l-Lys-Gly-l-His and l-Arg-Gly-l-His complexes. The ionic interaction between the positively charged lysine or arginine residues and the negatively charged DNA phosphodiester backbone may result in the reduced dissociation of these complexes when bound to the DNA minor groove.