Evidence That a Miniature Cu<sup>I</sup> Metalloprotein Undergoes Collisional Electron Transfer in the Inverted Marcus Region

Hong, Jing; Kharenko, Olesya A.; Fan, Jiufeng; Xie, Fang; Petros, Amy K.; Gibney, Brian R.; Ogawa, Michael Y.

doi:10.1002/anie.200601517

Cited by 20 publications

(21 citation statements)

References 23 publications

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“…It is within this context that our group has been studying the metal-binding properties of a cysteine-containing polypeptide called C16C19-GGY [9][10][11][12]. As previously reported by our group, the sequence of C16C19-GGY is based on a two-stranded a-helical coiled-coil [13,14,15] but modified to incorporate a Cys-X-X-Cys metal-binding motif along its hydrophobic face.…”

Section: Introductionmentioning

confidence: 91%

Cu(I) binding properties of a designed metalloprotein

Xie

Sutherland

Stillman

et al. 2010

Journal of Inorganic Biochemistry

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Section: Introductionmentioning

confidence: 91%

Cu(I) binding properties of a designed metalloprotein

Xie

Sutherland

Stillman

et al. 2010

Journal of Inorganic Biochemistry

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“…Examples of Cu(I) (13,14) and Cu(II) de novo designed helix bundles have been reported (15)(16)(17)(18)(19)(20)(21)(22)(23)(24). However, only a few examples of controlled binding of copper at (His) 3 sites are known (17,20,21).…”

Section: +mentioning

confidence: 99%

“…However, only a few examples of controlled binding of copper at (His) 3 sites are known (17,20,21). Although Cu(I)/(II) redox processes were presented for a few systems (13,14,22), none was fully characterized in both oxidation states, which is essential for catalytic copper redox protein designs. We felt that Cu(TRIL23H) 3 n+ [TRIL23H = (Ac-G[LKALEEK] 3 [HKALEEK]G-NH 2 )] was an ideal system to cycle between Cu(I) and Cu(II), because an X-ray crystal structure of Zn(II) bound to three histidines in the related peptide Hg S Zn N (CSL9CL23H) 3 + was known ( Fig.…”

Section: +mentioning

confidence: 99%

Designing a functional type 2 copper center that has nitrite reductase activity within α-helical coiled coils

Tegoni

Yu²,

Bersellini

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

101

188

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One of the ultimate objectives of de novo protein design is to realize systems capable of catalyzing redox reactions on substrates. This goal is challenging as redox-active proteins require design considerations for both the reduced and oxidized states of the protein. In this paper, we describe the spectroscopic characterization and catalytic activity of a de novo designed metallopeptide Cu(I/II)(TRIL23H) 3 +/2+ , where Cu(I/II) is embeded in α-helical coiled coils, as a model for the Cu T2 center of copper nitrite reductase. In Cu(I/II)(TRIL23H) 3 +/2+ , Cu(I) is coordinated to three histidines, as indicated by X-ray absorption data, and Cu(II) to three histidines and one or two water molecules. Both ions are bound in the interior of the three-stranded coiled coils with affinities that range from nano- to micromolar [Cu(II)], and picomolar [Cu(I)]. The Cu(His) 3 active site is characterized in both oxidation states, revealing similarities to the Cu T2 site in the natural enzyme. The species Cu(II)(TRIL23H) 3 2+ in aqueous solution can be reduced to Cu(I)(TRIL23H) 3 + using ascorbate, and reoxidized by nitrite with production of nitric oxide. At pH 5.8, with an excess of both the reductant (ascorbate) and the substrate (nitrite), the copper peptide Cu(II)(TRIL23H) 3 2+ acts as a catalyst for the reduction of nitrite with at least five turnovers and no loss of catalytic efficiency after 3.7 h. The catalytic activity, which is first order in the concentration of the peptide, also shows a pH dependence that is described and discussed.

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“…[10][11][12][13][14][15][16][17][18][19] These self-assembled structures are common non-covalent oligomerization sites for proteins which consist of an intertwining of two or more α-helices which run in either a parallel or antiparallel direction. 20 Coiled-coils are stabilized by a specific "knobs into holes" packing arrangement of hydrophobic amino acid side-chains in which a side-chain from one α-helix packs into a cavity formed by four side-chains of the complementary helix and form the hydrophobic core of the structure.…”

Section: α α α α α-Helical Coiled-coilsmentioning

confidence: 99%

“…It was further shown ( Figure 5) that the emission quenching rate constants decrease with increasing driving force, indicating that the system is in the inverted Marcus region. 11 The observation of decreasing ET rates with increasing driving force has long been observed in unimolecular, 25 or otherwise diffusionally-restricted donor/acceptor systems. 26,27 However, such behavior has rarely been seen in situations in which the donor and acceptor complexes are allowed to freely diffuse in solution where high driving force reactions usually occur at the diffusion limit.…”

Section: A Luminescent Cumentioning

confidence: 99%

Electron-transfer functionality of synthetic coiled-coil metalloproteins

Ogawa

Fan

Fedorova

et al. 2006

J. Braz. Chem. Soc.

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O campo emergente da engenharia molecular de metaloproteínas visa preparar proteínas artificiais, cujas propriedades podem imitar e talvez até mesmo melhorar várias características encontradas nas metaloenzimas naturais. Este artigo de revisão resume nossos esforços recentes na preparação de metaloproteínas sintéticas, construídas a partir de "coiled-coils" alfa-hélices, e na incorporação de grupos de transferência de elétrons nesses sistemas. Recentemente, concebemos uma cisteína contendo um peptídeo com hélice randômica, o qual forma uma estrutura "coiled-coil" alfa-helicoidal ao se ligar a vários metais. O aduto de Cu I pode atuar como agente fotoindutor de transferência de elétrons para receptores exógenos, e transfere elétrons por colisão na região invertida de Marcus para várias aminas de rutênio, as quais atuam como receptores. Especula-se que este resultado inesperado advenha do posicionamento do cofator de Cu I no interior da porção hidrofóbica da proteína, o qual proíbe a aproximação entre o doador e o receptor, diminuindo a velocidade de transferência eletrônica daquelas reações termodinamicamente muito favorecidas, para velocidades inferiores à do limite difusional.The emerging field of metalloprotein design seeks to prepare artificial proteins whose properties can mimic, enhance, and perhaps improve upon many features found in natural metalloenzymes. This review summarizes our recent efforts to prepare synthetic metalloproteins built from α-helical coiled-coils and to incorporate electron-transfer functionality within these systems. We have recently designed a cysteine-containing random-coil peptide which forms a α-helical coiled-coil upon binding various metals. The Cu I adduct can serve as photoinduced electron-transfer agent to exogenous acceptors and undergoes collisional electron-transfer in the inverted Marcus region to various ruthenium ammine acceptors. It is speculated that this unexpected result might be due to the positioning of the Cu I cofactor within the hydrophobic core of the protein which prohibits close approach between the donor and acceptor to slow the high driving force reaction rates below the diffusion limit.

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Evidence That a Miniature Cu^I Metalloprotein Undergoes Collisional Electron Transfer in the Inverted Marcus Region

Cited by 20 publications

References 23 publications

Cu(I) binding properties of a designed metalloprotein

Cu(I) binding properties of a designed metalloprotein

Designing a functional type 2 copper center that has nitrite reductase activity within α-helical coiled coils

Electron-transfer functionality of synthetic coiled-coil metalloproteins

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Evidence That a Miniature CuI Metalloprotein Undergoes Collisional Electron Transfer in the Inverted Marcus Region

Cited by 20 publications

References 23 publications

Cu(I) binding properties of a designed metalloprotein

Cu(I) binding properties of a designed metalloprotein

Designing a functional type 2 copper center that has nitrite reductase activity within α-helical coiled coils

Electron-transfer functionality of synthetic coiled-coil metalloproteins

Contact Info

Product

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Evidence That a Miniature Cu^I Metalloprotein Undergoes Collisional Electron Transfer in the Inverted Marcus Region