In: Angewandte Chemie, 2013, vol. 125, no. 17, p. 4780-4783
Einkristall-zu-Einkristall-Umwandlungen sind durch Ionenaustausch- und Transportreaktionen durch supramolekulare Kanäle möglich, die aus Kronenether- Molekülen bestehen und Trihalogenid-Ionen als Gerüst nutzen. In kinetischen Messungen des Ionentransports bei unterschiedlichen Temperaturen wurde die Aktivierungsenergie für solche Systeme bestimmt, und ein schneller Austausch zwischen K+-...
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In: Angewandte Chemie, 2015, vol. 127, no. 10, p. 2954-2958
Einige Mikroorganismen zeigen anaerobe mineralische Respiration, bei der sie Metallionen zu Metallnanopartikeln reduzieren. Hierbei werden Peptide als Medium für den Elektronentransfer (ET) verwendet. Diese Reaktionsklasse wird anhand eines Modellpeptids und Silber als Metall diskutiert. Erstaunlicherweise können Silberionen, die von Peptiden mit Histidin als silberbindender Aminosäure und...
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In: Particle & Particle Systems Characterization, 2020, vol. 37, no. 5, p. 1900419
Metal nanoparticles (NPs), chalcogenides, and carbon quantum dots can be easily synthesized from whole microorganisms (fungi and bacteria) and cell‐free sterile filtered spent medium. The particle size distribution and the biosynthesis time can be somewhat controlled through the biomass/metal solution ratio. The biosynthetic mechanism can be explained through the ion‐reduction theory and...
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In: Particle & Particle Systems Characterization, 2020, vol. 37, no. 5, p. 1900419
Metal nanoparticles (NPs), chalcogenides, and carbon quantum dots can be easily synthesized from whole microorganisms (fungi and bacteria) and cell‐free sterile filtered spent medium. The particle size distribution and the biosynthesis time can be somewhat controlled through the biomass/metal solution ratio. The biosynthetic mechanism can be explained through the ion‐reduction theory and...
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In: Angewandte Chemie International Edition, 2020, vol. 59, no. 30, p. 12331-12336
Anaerobic microorganisms of the Geobacter genus are effective electron sources for the synthesis of nanoparticles, for bioremediation of polluted water, and for the production of electricity in fuel cells. In multistep reactions, electrons are transferred via iron/heme cofactors of c‐type cytochromes from the inner cell membrane to extracellular metal ions, which are bound to outer membrane...
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In: ChemBioChem, 2018, vol. 19, no. 9, p. 922–926
In nature, proteins serve as media for long‐distance electron transfer (ET) to carry out redox reactions in distant compartments. This ET occurs either by a single‐step superexchange or through a multi‐step charge hopping process, which uses side chains of amino acids as stepping stones. In this study we demonstrate that Phe can act as a relay amino acid for long‐distance electron...
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In: Journal of Physical Organic Chemistry, 2015, vol. 28, no. 5, p. 347–353
Long distance electron transfer in proteins requires relay stations that can be transitorily oxidized or reduced. Although individual prolines cannot assume this function, because of their high ionization energy, it has been shown that polyprolines have the ability to transfer charges. In order to determine the role of the proline in the hole distribution and transport within a PheProPhe...
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In: Angewandte Chemie International Edition, 2015, vol. 54, no. 10, p. 2912–2916
Some microorganisms perform anaerobic mineral respiration by reducing metal ions to metal nanoparticles, using peptide aggregates as medium for electron transfer (ET). Such a reaction type is investigated here with model peptides and silver as the metal. Surprisingly, Ag⁺ ions bound by peptides with histidine as the Ag⁺-binding amino acid and tyrosine as photoinducible electron donor cannot...
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In: The Journal of Physical Chemistry B, 2014, vol. 118, no. 16, p. 4261–4272
Charge transfer in peptides and proteins can occur on different pathways, depending on the energetic landscape as well as the coupling between the involved orbitals. Since details of the mechanism and pathways are difficult to access experimentally, different modeling strategies have been successfully applied to study these processes in the past. These can be based on a simple empirical pathway...
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In: Chemical Reviews, 2013, vol. 113, no. 7, p. 4708–4754
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