Berlin Scientists Unlock Nature's CO2 Conversion Secret
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Researchers at Berlin's Humboldt University have made a breakthrough discovery that could transform how we handle carbon dioxide emissions. Working within the Cluster of Excellence "Unifying Systems in Catalysis (UniSysCat)," scientists have decoded how bacteria naturally convert the greenhouse gas CO2 into valuable chemical compounds.
The research, published in two studies in the prestigious journal Nature Catalysis, focuses on two nickel-containing enzymes: carbon monoxide dehydrogenase (CODH) and acetyl-CoA synthase (ACS). These biological catalysts work together to transform CO2 first into carbon monoxide, then into activated acetic acid through the ancient Wood-Ljungdahl pathway.
According to information from Humboldt University's press release, the key lies in the unique behavior of nickel ions. Professor Holger Dobbek, who leads the Structural Biology and Biochemistry research group, explains that the nickel ion doesn't just bind CO2 – it also provides the electrons needed for the reaction. Using advanced X-ray diffraction and spectroscopy, his team visualized all catalytic states at atomic resolution for the first time.
"Since our first structure of Ni-containing carbon monoxide dehydrogenases in 2001, I have wondered why these enzymes need Ni ions. Our new work provides an answer," Dobbek notes.
The complementary study, led by Professor Petra Wendler from the University of Potsdam, used cryo-electron microscopy to reveal six previously unknown intermediate states of the ACS enzyme, showing how structural changes control the entire reaction process.
These insights could lead to synthetic catalysts that efficiently convert CO2 into valuable chemicals, supporting Berlin's position as a hub for sustainable innovation and contributing to the circular economy.