X-ray absorption spectroscopic studies of high valent iron porphyrins. Horseradish peroxidase compounds I and II and synthetic models.
X-ray absorption spectroscopic studies of high valent iron porphyrins. Horseradish peroxidase compounds I and II and synthetic models.
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DOI：
10.1016/s0021-9258(17)44029-4
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发表时间：
1983-11
期刊：
影响因子：
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通讯作者：
J. Penner‐Hahn;T. McMurry;M. Renner;L. Latos-Grazynsky;K. Eble;I. M. Davis;A. Balch;J. Groves;J. Dawson;K. Hodgson
中科院分区：
文献类型：
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作者：
J. Penner‐Hahn;T. McMurry;M. Renner;L. Latos-Grazynsky;K. Eble;I. M. Davis;A. Balch;J. Groves;J. Dawson;K. Hodgson
X-射线吸收边和扩展的X-射线吸收精细结构的研究已进行休息（铁）辣根过氧化物酶，HRP化合物I（HRP-I），HRP化合物II（HRP-II），和几个高度氧化的合成铁卟啉，可能有相关的铁网站在辣根过氧化物酶的模型。的吸收边的能量是一致的Fe（IV）配方的高度氧化的物种。吸收边的形状进一步支持HRP-I和模型化合物之一的Fe（IV）-卟啉π-阳离子的分配。边缘形状也表明，铁网站的模型卟啉是不相同的铁网站的酶。扩展的X射线吸收精细结构的初步曲线拟合分析清楚地表明存在两个不同的最近邻距离的铁，无论是在HRP-I和HRP-II，以及在两个高度氧化的模型卟啉。这些距离被解释为铁-卟啉氮距离和短（约1.6 A）铁-氧距离。
X-ray absorption edge and extended x-ray absorption fine structure studies have been undertaken on resting (ferric) horseradish peroxidase, HRP compound I (HRP-I), HRP compound II (HRP-II), and several highly oxidized synthetic iron porphyrins that may have relevance as models for the iron site in horseradish peroxidase. The energies of the absorption edges are consistent with an Fe(IV) formulation for the highly oxidized species. The shapes of the absorption edges further support the assignment of HRP-I and one of the model compounds as Fe(IV)-porphyrin pi-cations. The edge shapes also demonstrate that the iron sites in the model porphyrins are not identical to the iron sites in the enzyme. Preliminary curve fitting analysis of the extended x-ray absorption fine structure clearly indicates the presence of two different nearest neighbor distances for the iron, both in HRP-I and HRP-II, as well as in two of the highly oxidized model porphyrins. These distances are interpreted as an iron-porphyrin nitrogen distance and as a short (approximately 1.6 A) iron-oxygen distance.