A water-soluble supramolecular complex that mimics the heme/copper hetero-binuclear site of cytochrome<i>c</i>oxidase

Kitagishi, Hiroaki; Shimoji, Daiki; Ohta, Takao; Kamiya, Ryo; Kudo, Yotaro; Onoda, Akira; Hayashi, Takashi; Weiss, Jean; Wytko, Jennifer A.; Kawasaki, Koji

doi:10.1039/c7sc04732k

Cited by 30 publications

(26 citation statements)

References 45 publications

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“…The experimental results showed these materials had poor catalytic efficiency compared to biomimetic mineralization under the same experimental conditions, which elucidated that the mineralization process was important to improve the catalytic activity of Cyt c. This observation was consistent with that reported by Jianget al [26]. The reason for the catalytic efficiency (k cat /K m ) increased from 35.7 to 705 M −1 s −1 (Table 2) might be the formation of a bimetallic center provided by Cu(Im) 2 and the ferric porphyrin of Cyt c [5,35], or a new catalytic site formed by Cu(Im) 2 and coordinating amino acids on the protein surface [5]. Based on the composite of Cyt c@Cu(Im) 2 , we also constructed a multi-enzyme system of GOx-Cyt c@Cu(Im) 2 using asimilar procedureas for a single enzyme.…”

Section: Peroxidase Activity Assay Of Free Cyt C and Cyt C@cu(im)2supporting

confidence: 88%

Biomimetic Mineralization of Cytochrome c Improves the Catalytic Efficiency and Confers a Functional Multi-Enzyme Composite

Gong

Wei

et al. 2019

Catalysts

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The encapsulated enzyme system by metal-organic frameworks (MOFs) exhibits great potential in biofuel cells, pharmaceuticals, and biocatalysis. However, the catalytic efficiency and the enzymatic activity are severely hampered due to enzyme leaching and deficiency of storage stability. In this study, we immobilized cytochrome c (Cyt c) into dimethylimidazole-copper (Cu(Im) 2 ) by biomimetic mineralization, and constructed a bioinorganic hybrid material, termed Cyt c@Cu(Im) 2 . Encapsulated Cyt c in Cu(Im) 2 with a nanosheet structure exhibited significantly improved catalytic efficiency, enzymatic activity and kinetic performance. The catalytic efficiency (k cat /K m ) for Cyt c@Cu(Im) 2 was~20-fold higher compared to that of free Cyt c. Moreover, the increased activity was not affected by long-term storage. Based on this system, we further constructed a multi-enzyme composite with glucose-oxidase (GOx), termed GOx-Cyt c@Cu(Im) 2 , which exhibited greatly improved enzymatic activity, stability, and excellent selectivity for the detection of low concentrations of glucose. This strategy may provide new insights into the design of enzymes with high activity and stability, as well as the construction of multi-enzyme systems.

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Section: Peroxidase Activity Assay Of Free Cyt C and Cyt C@cu(im)2supporting

confidence: 88%

Biomimetic Mineralization of Cytochrome c Improves the Catalytic Efficiency and Confers a Functional Multi-Enzyme Composite

Gong

Wei

et al. 2019

Catalysts

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“…The 4 e − ORR is required in many energy conversion techniques, [4–7] while the 2 e − ORR makes H 2 O 2 , which is a widely used industrial oxidant and also a promising fuel [8–10] . Recently, many molecular ORR catalysts have been reported [1–5, 11–28] . Although achievements have been made in improving the 4 e − ORR by providing rapid electron and proton transfers, [17, 29, 30] introducing hydrogen‐bonding [31, 32] and electrostatic interactions, [33] and using dinuclear cooperation, [34–38] realizing these functionalities is challenging from both design and synthesis points of view.…”

Section: Methodsmentioning

confidence: 99%

Controlling Oxygen Reduction Selectivity through Steric Effects: Electrocatalytic Two‐Electron and Four‐Electron Oxygen Reduction with Cobalt Porphyrin Atropisomers

Guo

et al. 2021

Angewandte Chemie

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Achieving a selective 2 e À or 4 e À oxygen reduction reaction (ORR) is critical but challenging. Herein, we report controlling ORR selectivity of Co porphyrins by tuning only steric effects. We designed Co porphyrin 1 with meso-phenyls each bearing a bulky ortho-amido group. Due to the resulted steric hinderance, 1 has four atropisomers with similar electronic structures but dissimilar steric effects. Isomers abab and aaaa catalyze ORR with n = 2.10 and 3.75 (n is the electron number transferred per O 2 ), respectively, but aabb and aaab show poor selectivity with n = 2.89-3.10. Isomer abab catalyzes 2 e À ORR by preventing a bimolecular O 2 activation path, while aaaa improves 4 e À ORR selectivity by improving O 2 binding at its pocket, a feature confirmed by spectroscopy methods, including O K-edge near-edge X-ray absorption fine structure. This work represents an unparalleled example to improve 2 e À and 4 e À ORR by tuning only steric effects without changing molecular and electronic structures.

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“…In very recent work, H. Kitagishi et al 1021 prepared a new porphyrin/cyclodextrin supramolecular complex that serves as a CcO model in aqueous media. The design of this model system was facilitated by the propensity of per-o-methylated β - cyclodextrins to form stable 1:2 complexes with porphyrin molecules such as 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrinato iron(III) [(TPPS)Fe III ] + .…”

Section: Small Molecule Synthetic Models Of Heme-copper Oxidasesmentioning

confidence: 99%

Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function

et al. 2018

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Heme-copper oxidases (HCOs) are terminal enzymes on the mitochondrial or bacterial respiratory electron transport chain, which utilize a unique heterobinuclear active site to catalyze the 4H+/4e− reduction of dioxygen to water. This process involves a proton-coupled electron transfer (PCET) from a tyrosine (phenolic) residue and additional redox events coupled to transmembrane proton pumping and ATP synthesis. Given that HCOs are large, complex, membrane-bound enzymes, bioinspired synthetic model chemistry is a promising approach to better understand heme-Cu-mediated dioxygen reduction, including the details of proton and electron movements. This review encompasses important aspects of heme-O2 and copper–O2 (bio)chemistries as they relate to the design and interpretation of small molecule model systems and provides perspectives from fundamental coordination chemistry, which can be applied to the understanding of HCO activity. We focus on recent advancements from studies of heme–Cu models, evaluating experimental and computational results, which highlight important fundamental structure–function relationships. Finally, we provide an outlook for future potential contributions from synthetic inorganic chemistry and discuss their implications with relevance to biological O2-reduction.

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A water-soluble supramolecular complex that mimics the heme/copper hetero-binuclear site of cytochromecoxidase

Abstract: The O2 adduct of an aqueous synthetic heme/copper model system built on a porphyrin/cyclodextrin supramolecular complex has been characterized.

Cited by 30 publications

References 45 publications

Biomimetic Mineralization of Cytochrome c Improves the Catalytic Efficiency and Confers a Functional Multi-Enzyme Composite

Biomimetic Mineralization of Cytochrome c Improves the Catalytic Efficiency and Confers a Functional Multi-Enzyme Composite

Controlling Oxygen Reduction Selectivity through Steric Effects: Electrocatalytic Two‐Electron and Four‐Electron Oxygen Reduction with Cobalt Porphyrin Atropisomers

Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function

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