Copper(II) complexes of several monophosphono dipeptides: the role of phosphonic oxygen and thioether sulfur in complex stabilization
Copper(II) complexes of several monophosphono dipeptides: the role of phosphonic oxygen and thioether sulfur in complex stabilization
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DOI：
10.1016/j.poly.2004.04.027
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发表时间：
2004-07
期刊：
影响因子：
2.6
通讯作者：
B. Kurzak;A. Woźna;J. Jezierska;M. Jeżowska‐Bojczuk;W. Szczepanik;P. Kafarski
中科院分区：
文献类型：
--
作者：
B. Kurzak;A. Woźna;J. Jezierska;M. Jeżowska‐Bojczuk;W. Szczepanik;P. Kafarski
用电位法、紫外-可见光谱、圆二色谱和电子顺磁共振研究了铜(II)氧氮给体络合物(单膦二肽：1-(N-L-亮氨基)甲基膦酸-亮氨酸(P)，1-(N-L-亮氨基)钒膦酸-亮氨酸(P))和一个硫醚硫给体络合物(单膦二肽：1-N-(glycyloamino)-2-(S-benzylthio)ethanephosphonic酸-甘氨酸-(BZ)Cys(P)，d(+)和Gly-(BZ)Cys(P)，d(−))。铜(II)与二肽的络合反应非常相似，在宽pH范围内以[MLH−1]−为主。然而，圆二色谱是一种非常灵敏的工具，可以用来解释多肽复合体之间的微小结构差异，包括硫醚残基在轴向和赤道位置的弱相互作用。硫醚给体的配合物具有较高的热力学稳定常数。
Potentiometric, UV–Vis, CD and EPR studies were performed on the copper(II) complexes of oxygen and nitrogen donor ligands (monophosphono dipeptides: 1-(N-l-leucylamino)methylphosphonic acid – Leu–Gly(P), 1-(N-l-leucylamino)valylphosphonic acid – Leu–Val(P)) and a thioether sulfur donor ligands (monophosphono dipeptides: 1-N-(glycyloamino)-2-(S-benzylthio)ethanephosphonic acid – Gly–(Bz)Cys(P), d(+) and Gly–(Bz)Cys(P), d(−)). Complex formation reaction between copper(II) and dipeptides were very similar to each other, [MLH−1]−being the major species in wide pH region. CD spectroscopy, however, was a very sensitive tool for the elucidation of small structural differences among peptide complexes, including the weak interaction in an axial and equatorial position of thioether residues. The complexes of the thioether donors have higher thermodynamic stability constants than the other ones.