Iron(II/III) Halide Complexes Promote the Interconversion of Nitric Oxide and S -Nitrosothiols through Reversible Fe-S Interaction
Iron(II/III) Halide Complexes Promote the Interconversion of Nitric Oxide and S -Nitrosothiols through Reversible Fe-S Interaction
复制标题
铁(II/III)卤化物配合物通过可逆的Fe-S相互作用促进一氧化氮和S-亚硝基硫醇的相互转化
DOI：
10.1021/acs.inorgchem.1c00203
复制
发表时间：
2021
影响因子：
4.6
通讯作者：
Zhang, Shiyu
中科院分区：
文献类型：
--
作者：
Poptic, Anna L.;Zhang, Shiyu
生物体内的血红素铁和非血红素铁介导了S-亚硝基硫醇类化合物对NO·的储存和释放，从而控制NO·的生物浓度。尽管它们在许多生理过程中的重要性，在Fe中心的N-S键形成/裂解的机制一直是有争议的。本文报道了Fe Ⅱ/FeIII氯配合物介导的NO·和S-亚硝基硫醇的相互转化。2当量的S-亚硝基硫醇（Ph_3CSNO）与[Cl_6FeII_2]_2 ~-反应，容易释放出NO·，生成卤代硫醇铁（III）。详细的光谱研究，包括原位紫外可见光谱，红外光谱和钼穆斯堡尔光谱，支持的相互作用的S原子与FeII中心。这与已被广泛研究的“红色产物”[（CN）5 Fe（κ1-N-RSNO）]3-[（CN）5 Fe（κ1-N-RSNO）]3-释放NO·的机理相反。此外，FeIII还可通过S-亚硝基硫醇的形成介导NO·的储存。用2当量的NO·处理卤代硫醇铁（III），生成Ph 3CSNO，其中Fe II源被捕获为S = 3/2 {FeNO} 7物种[Cl 3FeNO]−，其对S-亚硝基硫醇的进一步配位和活化是惰性的。我们的工作证明了不稳定铁如何介导NO·/硫醇盐和S-亚硝基硫醇的相互转化，这对自然界如何管理游离NO·的生物浓度具有重要意义。
Heme and non-heme iron in biology mediate the storage/release of NO•fromS-nitrosothiols as a means to control the biological concentration of NO•. Despite their importance in many physiological processes, the mechanisms of N–S bond formation/cleavage at Fe centers have been controversial. Herein, we report the interconversion of NO•andS-nitrosothiols mediated by FeII/FeIIIchloride complexes. The reaction of 2 equiv ofS-nitrosothiol (Ph3CSNO) with [Cl6FeII2]2–results in facile release of NO•and formation of iron(III) halothiolate. Detailed spectroscopic studies, including in situ UV–vis, IR, and Mössbauer spectroscopy, support the interaction of the S atom with the FeIIcenter. This is in contrast to the proposed mechanism of NO•release from the well-studied “red product” κ1-N boundS-nitrosothiol FeIIcomplex, [(CN)5Fe(κ1-N-RSNO)]3–. Additionally, FeIIIchloride can mediate NO•storage through the formation ofS-nitrosothiols. Treatment of iron(III) halothiolate with 2 equiv of NO•regenerates Ph3CSNO with the FeIIsource trapped as theS= 3/2 {FeNO}7species [Cl3FeNO]−, which is inert toward further coordination and activation ofS-nitrosothiols. Our work demonstrates how labile iron can mediate the interconversion of NO•/thiolate andS-nitrosothiol, which has important implications toward how Nature manages the biological concentration of free NO•.