Adduct formation between ternary Pt(II)–amino acid–aromatic diimine complexes and flavin mononucleotide and its effect on redox properties
Adduct formation between ternary Pt(II)–amino acid–aromatic diimine complexes and flavin mononucleotide and its effect on redox properties
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DOI：
10.1016/j.ica.2008.03.054
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发表时间：
2009-02
影响因子：
2.8
通讯作者：
Y. Nakabayashi;M. Tashiro;T. Yajima;M. Takani;A. Tani;Takeshi Motoyama;A. Odani;O. Yamauchi
中科院分区：
文献类型：
--
作者：
Y. Nakabayashi;M. Tashiro;T. Yajima;M. Takani;A. Tani;Takeshi Motoyama;A. Odani;O. Yamauchi
由氨基酸和芳香族二亚胺组成的三元 Pt(II) 络合物 [Pt(A)(DA)]（A=甘氨酸 (Gly)、丙氨酸 (Ala)、缬氨酸或精氨酸 (Arg)；DA=2,2'-联吡啶 (bpy) 或 1,10-菲咯啉 (phen)）与黄素单核苷酸 (FMN) 和通过光谱、X 射线衍射和电化学方法研究了蒽醌-2-磺酸盐 (AQS)。 Pt(II)配合物通过与FMN的芳香族部分堆积形成1:1的[Pt(A)(DA)]–FMN加合物，并且根据1H NMR谱确定具有[Pt(A)(phen)]（A=Gly、Ala和Arg）和[Pt(Arg)(bpy)]的体系的稳定常数logK为2.83(8)–3.42(6) 25°C 下，在 D2O 中（I=var.）。通过 X 射线分析确定加合物 [Pt(Ala)(phen)](AQS) (1) 的结构涉及配位 phen 与 AQS 之间距离为 3.400(7)Å 的 π-π 堆积相互作用以及 AQS 的磺酸盐部分与配位 Ala 的氨基之间的氢键。 1:1 [Pt(A)(DA)]-FMN 体系的循环伏安法在磷酸盐缓冲液（pH 7.0）中的结果表明，与游离 FMN 的值相比，FMN 的双电子氧化还原过程的电势 E1/2 移动到更高的值 18-31mV。
Adduct formation of ternary Pt(II) complexes composed of an amino acid and an aromatic diimine, [Pt(A)(DA)] (A=glycinate (Gly), alaninate (Ala), valinate, or arginine (Arg); DA=2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen)), with flavin mononucleotide (FMN) and anthraquinone-2-sulfonate (AQS) were investigated by spectroscopic, X-ray diffraction, and electrochemical methods. The Pt(II) complexes formed 1:1 [Pt(A)(DA)]–FMN adducts by stacking with the aromatic moiety of FMN, and the stability constants, logK, for the systems with [Pt(A)(phen)] (A=Gly, Ala, and Arg) and [Pt(Arg)(bpy)] were determined to be 2.83(8)–3.42(6) from1H NMR spectra at 25°C in D2O (I=var.). The structure of the adduct [Pt(Ala)(phen)](AQS) (1) was determined by X-ray analysis to involve a π–π stacking interaction between coordinated phen and AQS with the distance of 3.400(7)Å and a hydrogen bond between the sulfonate moiety of AQS and the amino group of coordinated Ala. Cyclic voltammetry of the 1:1 [Pt(A)(DA)]–FMN systems in a phosphate buffer (pH 7.0) showed that the potentials, E1/2, for the two-electron redox process of FMN shifted to higher values by 18–31mV as compared with the value for free FMN.