idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Thema Corona

Imagefilm
Science Video Project
idw-News App:

AppStore



Share on: 
12/18/2020 18:58

Discovery of a new catalytic intermediate in biological water oxidation

Isabel Schiffhorst Presse- und Öffentlichkeitsarbeit
Max-Planck-Institut für Kohlenforschung

    Computational simulations performed by the Pantazis group combined with spectroscopic studies led to the discovery of a new catalytic intermediate in water oxidation.

    One of the greatest ambitions of modern chemistry is to reproduce with synthetic catalysts the remarkable feat of water oxidation performed in nature by photosynthetic organisms. Plants use sunlight to split water into oxygen, protons, and electrons. This is the source of the oxygen that we breathe, while the protons and electrons are used in the enzymatic reactions that incorporate atmospheric carbon dioxide into biomolecules. Despite decades of dedicated research efforts, many details of nature’s process remain shrouded in mystery. Very recently, a significant step towards deciphering the mechanism of water oxidation by plants was made by an international team of researchers led by Dr. Dimitrios Pantazis, group leader at the Max-Planck-Institut für Kohlenforschung.

    Guided by spectroscopic studies and computational simulations performed by the Pantazis group during the past few years, the research team designed a series of experiments that intended to inhibit the binding of water at the active site of the enzyme responsible for water oxidation, Photosystem II. Using methanol as an inhibitor to block a protein channel that delivers water to the catalytic site, it was possible to isolate and study a previously unknown form of the catalyst, the intermediate that is responsible for binding and activating the water molecule for subsequent oxidation. Using electron paramagnetic resonance (EPR) spectroscopy in combination with advanced quantum chemical techniques, this previously unknown intermediate state was shown to contain a manganese ion with a very unusual coordination geometry that has no exact precedence in synthetic chemistry. This manganese ion has only five instead of the normal six ligands and this creates an important free coordination site where water can bind. The discovery of the new catalytic intermediate makes it necessary to reconsider the hypothetical reaction mechanisms discussed so far for water oxidation in plants, but it also has important implications for the design and operational principles of artificial water splitting systems.

    The study is published as a “Hot Paper” in the prestigious journal Angewandte Chemie.


    Contact for scientific information:

    Dr. Dimitrios Pantazis, Group Leader at the Max-Planck-Institut für Kohlenforschung
    Phone: +49 208 306 2156


    Original publication:

    G. Zahariou, N. Ioannidis, Y. Sanakis, D. A. Pantazis. “Arrested Substrate Binding Resolves Catalytic Intermediates in Higher‐Plant Water Oxidation”, Angewandte Chemie International Edition. https://onlinelibrary.wiley.com/doi/10.1002/anie.202012304


    Attachment
    attachment icon Press release new catalytice intermediate in water oxidation

    Criteria of this press release:
    Journalists, Scientists and scholars
    Chemistry, Information technology
    transregional, national
    Research results, Scientific Publications
    English


    EPR spectroscopy and quantum chemistry probe the water oxidation catalyst of biological photosynthesis


    For download

    x

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).