Gating the electron transfer at a monocopper centre through the supramolecular coordination of water molecules within a protein chamber mimic

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F18%3A00498563" target="_blank" >RIV/61388963:_____/18:00498563 - isvavai.cz</a>

Result on the web

<a href="https://pubs.rsc.org/en/content/articlehtml/2018/sc/c8sc03124j" target="_blank" >https://pubs.rsc.org/en/content/articlehtml/2018/sc/c8sc03124j</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c8sc03124j" target="_blank" >10.1039/c8sc03124j</a>

Result language

angličtina

Original language name

Gating the electron transfer at a monocopper centre through the supramolecular coordination of water molecules within a protein chamber mimic

Original language description

Functionality of enzymes is strongly related to water dynamic processes. The control of the redox potential for metallo-enzymes is intimately linked to the mediation of water molecules in the first and second coordination spheres. Here, we report a unique example of supramolecular control of the redox properties of a biomimetic monocopper complex by water molecules. It is shown that the copper complex based on a calix[6]arene covalently capped with a tetradentate [tris(2-methylpyridyl)amine] (tmpa) core, embedding the metal ion in a hydrophobic cavity, can exist in three different states. The first system displays a totally irreversible redox behaviour. It corresponds to the reduction of the 5-coordinate mono-aqua-Cu-II complex, which is the thermodynamic species in the +II state. The second system is detected at a high redox potential. It is ascribed to an empty cavity or water-free state, where the Cu-I ion sits in a 4-coordinate trigonal environment provided by the tmpa cap. This complex is the thermodynamic species in the +I state under dry conditions. Surprisingly, a third redox system appears as the water concentration is increased. Under water-saturation conditions, it displays a pseudo-reversible behaviour at a low scan rate at the mid-point from the water-free and aqua species. This third system is not observed with the Cu-tmpa complex deprived of a cavity. In the calix[6]cavity environment, it is ascribed to a species where a pair of water molecules is hosted by the calixarene cavity. A molecular mechanism for the Cu-II/Cu-I redox process with an interplay of (H2O)(x) (x = 0, 1, 2) hosting is proposed on the basis of computational studies. Such an unusual behaviour is ascribed to the unexpected stabilization of the Cu-I state by inclusion of the pair of water molecules. This phenomenon strongly evidences the drastic influence of the interaction between water molecules and a hydrophobic cavity on controlling the thermodynamics and kinetics of the Cu-II/Cu-I electron transfer process.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Chemical Science

ISSN

2041-6520

e-ISSN

—

Volume of the periodical

9

Issue of the periodical within the volume

43

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

8282-8290

UT code for WoS article

000449701000014

EID of the result in the Scopus database

2-s2.0-85056327343