Synthesis, Characterization and Luminescence Properties of Dipyridin-2-ylamine Ligands and Their Bis(2,2′-bipyridyl)ruthenium(II) Complexes and Labelling Studies of Papain from Carica papaya
Synthesis, Characterization and Luminescence Properties of Dipyridin-2-ylamine Ligands and Their Bis(2,2′-bipyridyl)ruthenium(II) Complexes and Labelling Studies of Papain from Carica papaya
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DOI：
10.1002/ejic.201000585
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发表时间：
2010-11-01
影响因子：
2.3
通讯作者：
Salmain, Michele
中科院分区：
文献类型：
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作者：
Haquette, Pierre;Jacques, Julien;Salmain, Michele
两种发光聚吡啶Ru-II配合物，包括由马来酰亚胺基团官能化的联吡啶-2-胺(Dpa)配体，即[Ru(Bpy)(2)(1a-b)](Pf6)(2)(bpy=2，2‘-联吡啶，la=1[4-(联吡啶2-氨基)丁基]-1H-吡咯2，5-二酮，合成了Lb=1[5(联吡啶-2-胺)戊基]1H-吡咯-2-二酮，并求出了[Ru(Bpy)(2)(1b)](Pf6)(2)的X-射线结构。研究了这些配合物的光物理性质和起始联吡啶2-胺配体在最大吸收激发下的光物理性质。DPA配体由于马来酰亚胺基团的猝灭而表现出微弱的发光，相反，配合物表现出明显的发光波长，其发射波长为600 nm，源于配体的金属到配体电荷转移(MLCT)三重态反应，并且与半胱氨酸内切酶木瓜酶的配合物如马来酰亚胺的通常反应所预期的那样发生在单个游离半胱氨酸(Cys25)处。所得到的生物偶联化合物显示出分配给所连接的荧光团的发光，其中一种木瓜蛋白酶-Ru-II生物偶联物的圆二色谱在近紫外区显示出一条典型的双标记带，表明木瓜酶与RAc络合物的反应是立体选择性的，有利于Delta对映体
Two luminescent polypyridyl Ru-II complexes including dipyradin-2 ylamme (dpa) ligands functionalized by a maleimide group, namely [Ru(bpy)(2)(1a-b)](PF6)(2) (bpy = 2,2' bipyridyl, la = 1 [4-(dipyridin 2-ylamino)butyl]-1H-pyrrole 2 5 dione, lb = 1 [5 (dipyridin-2 ylammo)pentyl] 1H pyrrole 2 5 di one) were synthesized and the X ray structure of [Ru(bpy)(2) (1b)](PF6)(2) was solved The photophysical properties of these complexes and the starting dipyridin 2 ylamme ligands were studied Upon excitation at their maximum of absorption, the dpa ligands exhibited weak luminescence because of quenching by the maleimide group Conversely the complexes displayed noticeable luminescence with an emission wavelength at 600 nm that originated from a metal to-ligand charge-transfer (MLCT) triplet state Reaction of the ligands and the complexes with the cysteine endoproteinase papain was shown to occur at the single free cysteine (Cys25) as expected by the usual reactivity of maleimides The resulting bioconjugates displayed luminescence assigned to the attached fluorophore, and luminescence enhancement was ob served with respect to the starting reagents The circular dichroism spectrum of one of the papain-Ru-II bioconjugates displayed a typical bisignate band in the near UV range indicating that the reaction of papain with the rac complex appeared to be stereoselective in favour of the Delta enantiomer