Gleich zwei Nachhaltigkeitsforscher werden von der Gesellschaft Deutscher Chemiker (GDCh) für ihre Arbeiten gewürdigt. Professor Dr. Siegfried R. Waldvogel, Max-Planck-Institut für Chemische Energieko...

Weiter Wirtschafts-Chaos wegen Trumps Gaga-Zollpoliitk: Der S&P und andere US-Börsen brechen um massive 73 % ein.

Kurz vor der Wahl und nachdem die AfD offiziell ins Parteiprogramm getan hat, was Correctiv im Geheimtreffen enthüllte, gehen wieder zehntausende auf die Straße, dutzende Demos sind geplant. Hier die ...

Redox enzymes, mostly equipped with metal or organic cofactors, can vary their reactivity with oxygen by orders of magnitude. Understanding how oxygen reactivity is controlled by the protein milieu remains an open issue, with broad implications for mechanistic enzymology and enzyme design. Here, we address this problem by focusing on a widespread group of flavoenzymes that oxidize phenolic compounds derived from microbial lignin degradation, using either oxygen or cytochrome c as an electron acceptor. A comprehensive phylogenetic analysis revealed conserved amino acid motifs in the flavin-binding site. Using a combination of kinetic, mutagenesis, structural, and computational methods, we examined the role of these residues. Our results demonstrate that subtle and localized changes in the flavin environment can drastically impact oxygen reactivity. These effects are afforded through the creation or blockade of pathways for oxygen diffusion. Substrate binding plays a crucial role by potentially obstructing oxygen access to the flavin, thus influencing the enzyme’s reactivity. The switch between oxidase and dehydrogenase functionalities is thereby achieved through targeted, site-specific amino acid replacements that finely tune the microenvironment around the flavin. Our findings explain how very similar enzymes can exhibit distinct functional properties, operating as oxidases or dehydrogenases. They further provide valuable insights for the rational design and engineering of enzymes with tailored functions.

YouTube video by Robert Habeck