Bismercaptoethanediazacyclooctane as a N2S2 chelating agent and Cys-x-Cys mimic for Fe(NO) and Fe(NO)2
Bismercaptoethanediazacyclooctane as a N2S2 chelating agent and Cys-x-Cys mimic for Fe(NO) and Fe(NO)2
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DOI：
10.1021/ja049627y
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发表时间：
2004-09-08
影响因子：
15
通讯作者：
Darensbourg, MY
中科院分区：
文献类型：
--
作者：
Chiang, CY;Miller, ML;Darensbourg, MY
N-质子化的双巯基乙烷二氮杂环辛烷用作Enemark-Feltarn符号的氧化Fe（NO）（2）的双齿二硫代物配体，E-F {Fe（NO）（2）}（9）模拟Fe（NO）（2）与蛋白质或硫代生物分子的Cys-X-Cys结合。中性化合物的特征在于众所周知的g = 2.03 EPR信号，这是二亚硝酰铁络合物DNIC的标志。Fe（NO）（2）单元可以通过过量的PhS-从螯合物中除去，产生（PhS）（2）Fe（NO）（2）（-）。NO从Fe（H（+）bme-daco）（NO）（2）（v（NO）= 1740，1696 cm（-1））转移到[（bme-daco）Fe]（2）的Fell，得到五配位四方锥结构的N2 S2-Fe（NO）（v（NO）= 1649 cm（-1）），其中NO位于顶点位置。在g = 2.05处的各向同性EPR信号与E-F {Fe（NO）}（7）公式一致。在过量的NO中，红曲霉素的红色酯型分子形成为双核或四核物种，{（mu-SRS）[Fe-2（NO）（4）]}（n）（n =1，2）。这些良好的特征分子提供参考点的位置和模式在v（NO）振动光谱，预计是有用的铁氧还蛋白中的铁硫簇的NO降解的体内研究。
The N-protonated bismercaptoethanediazacyclooctane serves as a bidentate dithiolate ligand to oxidized Fe(NO)(2) of Enemark-Feltarn notation, E-F {Fe(NO)(2)},(9) mimicking Cys-X-Cys binding of Fe(NO)(2) to proteins or thio-biomolecules. The neutral compound is characterized by the well-known g = 2.03 EPR signal which is a hallmark of dinitrosyl iron complexes, DNIC's. The Fe(NO)(2) unit can be removed from the chelate by excess PhS-, producing (PhS)(2)Fe(NO)(2)(-). Transfer of NO from Fe(H(+)bme-daco)(NO)(2) (v(NO) = 1740, 1696 cm(-1)) to Fell of [(bme-daco)Fe](2) yields the five-coordinate, square-pyramidal N2S2-Fe(NO) (v(NO) = 1649 cm(-1)), where NO is in the apical position. Its isotropic EPR signal at g = 2.05 is consistent with E-F {Fe(NO)}(7) formulation. In excess NO, Roussin's red ester-type molecules are formed as dinuclear or tetranuclear species, {(mu-SRS)[Fe-2(NO)(4)]}(n) (n =1, 2). These well-characterized molecules furnish reference points for positions and patterns in v(NO) vibrational spectroscopy expected to be useful for in vivo studies of NO degradation of iron-sulfur clusters in ferredoxins.