Artificial Metalloproteins Containing Co(4)O(4) Cubane Active Sites.
Artificial Metalloproteins Containing Co(4)O(4) Cubane Active Sites.
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DOI：
10.1021/jacs.7b13052
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发表时间：
2018-02-28
影响因子：
15
通讯作者：
Borovik AS
中科院分区：
文献类型：
--
作者：
Olshansky L;Huerta-Lavorie R;Nguyen AI;Vallapurackal J;Furst A;Tilley TD;Borovik AS
利用生物素-链霉亲和素技术构建了含有Co 4 O 4立方烷活性位点的人工金属蛋白。通过氢键（H-键）稳定，在一系列固定化立方烷位点中从晶体学角度观察到末端和共面CoIII-OH 2部分。溶液电化学提供了氧化电位和pH值的相关性。对于含有Ser和Phe的金属辅因子附近的变体，1 e −/1H+化学占主导地位，直到pH值8，在此之上的氧化成为pH值无关。Tyr近端的Co 4 O 4活性位点的安装提供了一个单一的H-键的一组共面CoIII-OH 2基团之一。对于这种变体，观察到多-e −/多-H+化学，沿着在pH 9.5下的机制变化与Tyr去质子化一致。由于与光系统II的放氧复合物（氢键Tyr）和无定形水氧化催化剂（Co 4 O 4核心）的结构相似性，这些发现为水氧化的合成和生物系统架起了桥梁，突出了次级球相互作用在介导多电子−/多H+反应性中的重要性。
Artificial metalloproteins (ArMs) containing Co4O4 cubane active sites were constructed via biotin-streptavidin technology. Stabilized by hydrogen bonds (H-bonds), terminal and cofacial CoIII–OH2 moieties are observed crystallographically in a series of immobilized cubane sites. Solution electrochemistry provided correlations of oxidation potential and pH. For variants containing Ser and Phe adjacent to the metallocofactor, 1e−/1H+ chemistry predominates until pH 8, above which the oxidation becomes pH-independent. Installation of Tyr proximal to the Co4O4 active site provided a single H-bond to one of a set of cofacial CoIII–OH2 groups. With this variant, multi-e−/multi-H+ chemistry is observed, along with a change in mechanism at pH 9.5 that is consistent with Tyr deprotonation. With structural similarities to both the oxygen-evolving complex of photosystem II (H-bonded Tyr) and to amorphous water oxidation catalysts (Co4O4 core), these findings bridge synthetic and biological systems for water oxidation, highlighting the importance of secondary sphere interactions in mediating multi-e−/multi-H+ reactivity.
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影响因子：
8.4
作者：
Nguyen AI;Wang J;Levine DS;Ziegler MS;Tilley TD
通讯作者：
Tilley TD
影响因子：
2.6
作者：
Beattie, JK;Hambley, TW;Turner, P
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影响因子：
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作者：
Chakrabarty, Rajesh;Bora, Sanchay J.;Das, Birinchi K.
通讯作者：
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影响因子：
15
作者：
McAlpin, J. Gregory;Stich, Troy A.;Britt, R. David
通讯作者：
Britt, R. David
影响因子：
15
作者：
Kim, K;Cole, PA
通讯作者：
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