Serial Femtosecond Crystallography Reveals the Role of Water in the One- or Two-Electron Redox Chemistry of Compound I in the Catalytic Cycle of the B-Type Dye-Decolorizing Peroxidase DtpB.
Serial Femtosecond Crystallography Reveals the Role of Water in the One- or Two-Electron Redox Chemistry of Compound I in the Catalytic Cycle of the B-Type Dye-Decolorizing Peroxidase DtpB.
复制标题
连续飞秒晶体学揭示了水在B型染料脱色过氧化物酶DtpB的催化循环中化合物I的单电子或双电子氧化还原化学中的作用。
DOI：
10.1021/acscatal.2c03754
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发表时间：
2022-11-04
期刊：
影响因子：
12.9
通讯作者：
Worrall, Jonathan A. R.
中科院分区：
文献类型：
--
作者：
Lucic, Marina;Wilson, Michael T.;Tosha, Takehiko;Sugimoto, Hiroshi;Shilova, Anastasya;Axford, Danny;Owen, Robin L.;Hough, Michael A. .;Worrall, Jonathan A. R.
关键词：
控制高价Fe（IV）-O催化中间体，化合物I和II，在血红素酶与分子氧或过氧化氢反应后产生的反应性，是重要的功能。已经假设远端血红素袋水分子的存在（湿）或不存在（干）可以影响化合物I是否经历连续的单电子加成或协同的双电子还原。为了验证这一假设，我们调查的作用，水的血红素远端口袋的染料脱色过氧化物酶利用一系列飞秒晶体学和快速动力学研究相结合。在干燥的远端血红素部位，化合物I还原通过化合物II浓度低的机制进行。该反应显示出强烈的氘同位素效应，表明还原与质子吸收耦合。所得到的质子化的化合物II（Fe（IV）-OH）迅速还原为三价铁状态，从而呈现出双电子转移过程。在潮湿的场所，化合物I的还原更快，没有氘效应，并且产生高度聚集的化合物II，其随后被还原成三价铁形式。这项工作提供了一个明确的实验测试的假设先进的文献中，涉及顺序或协同电子转移到化合物I在潮湿或干燥的远端血红素网站。
Controlling the reactivity of high-valent Fe(IV)–O catalytic intermediates, Compounds I and II, generated in heme enzymes upon reaction with dioxygen or hydrogen peroxide, is important for function. It has been hypothesized that the presence (wet) or absence (dry) of distal heme pocket water molecules can influence whether Compound I undergoes sequential one-electron additions or a concerted two-electron reduction. To test this hypothesis, we investigate the role of water in the heme distal pocket of a dye-decolorizing peroxidase utilizing a combination of serial femtosecond crystallography and rapid kinetic studies. In a dry distal heme site, Compound I reduction proceeds through a mechanism in which Compound II concentration is low. This reaction shows a strong deuterium isotope effect, indicating that reduction is coupled to proton uptake. The resulting protonated Compound II (Fe(IV)–OH) rapidly reduces to the ferric state, giving the appearance of a two-electron transfer process. In a wet site, reduction of Compound I is faster, has no deuterium effect, and yields highly populated Compound II, which is subsequently reduced to the ferric form. This work provides a definitive experimental test of the hypothesis advanced in the literature that relates sequential or concerted electron transfer to Compound I in wet or dry distal heme sites.
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DOI：
10.1002/anie.202103010
发表时间：
2021-06-21
期刊：
Angewandte Chemie (International ed. in English)
影响因子：
--
作者：
Kwon H;Basran J;Pathak C;Hussain M;Freeman SL;Fielding AJ;Bailey AJ;Stefanou N;Sparkes HA;Tosha T;Yamashita K;Hirata K;Murakami H;Ueno G;Ago H;Tono K;Yamamoto M;Sawai H;Shiro Y;Sugimoto H;Raven EL;Moody PCE
通讯作者：
Moody PCE
DOI：
10.1073/pnas.1521664113
发表时间：
2016-02-02
影响因子：
11.1
作者：
Chreifi, Georges;Baxter, Elizabeth L.;Poulos, Thomas L.
通讯作者：
Poulos, Thomas L.
影响因子：
4.8
作者：
Hersleth, Hans-Petter;Uchida, Takeshi;Andersson, K. Kristoffer
通讯作者：
Andersson, K. Kristoffer
影响因子：
6.1
作者：
Barty A;Kirian RA;Maia FR;Hantke M;Yoon CH;White TA;Chapman H
通讯作者：
Chapman H
影响因子：
14.9
作者：
Davis IW;Leaver-Fay A;Chen VB;Block JN;Kapral GJ;Wang X;Murray LW;Arendall WB 3rd;Snoeyink J;Richardson JS;Richardson DC
通讯作者：
Richardson DC