The inorganic side of life

When we think of the fundamental building blocks of life, we typically picture organic molecules like DNA or proteins. But life also has an important inorganic component: Many reactions that keep cells running would not be possible without metals such as iron, copper, and manganese. More than half of all known proteins use metallic centers for catalytic processes that are essential for life. George Cutsail researches at precisely this interface between biology and inorganic chemistry. The Professor of Inorganic Chemistry utilizes highly specialized spectroscopic methods to better understand – and potentially improve – such processes.

The chemist had already specialized in spectroscopic methods, particularly electron paramagnetic resonance (EPR) spectroscopy, during his doctorate at Northwestern University (Illinois, USA). “This would ultimately become the basis of my research here in Munich,” recounts Cutsail. At the time, however, the American would not have predicted his research would take him to Germany one day. “If you’d asked me during my doctoral years whether I’d leave the United States, I’d have said no chance,” he grins. That being said, he wanted to strike out on new paths after his PhD and work with X-ray spectroscopy. This led him to the Max Planck Institute for Chemical Energy Conversion in Mülheim an der Ruhr, where he would lead his own research group before coming to LMU.

Catalysts inspired by nature

Cutsail’s main research interest is in enzymatic reactions which involve the conversion of chemical energy using metal-containing catalysts. An example is the conversion of methane into methanol by bacteria where copper-containing enzymes play a key role. “With the help of these enzymes, the bacteria are able to split the extremely stable carbon-hydrogen bonds of methane and incorporate oxygen – the result is methanol, which the bacteria then use as a carbon source.”

Methane is a powerful greenhouse gas and arises in large quantities during processes such as petroleum production. An efficient conversion of methane into liquid products that are easier to transport could therefore be commercially and environmentally useful, notes Cutsail. “Nature already does this chemical energy conversion very well,” he emphasizes. But the mechanisms behind it are not fully understood. His goal is to decode these biological principles and use this knowledge to develop better metal-based catalysts inspired by nature.

Observing reactions ‘live’

To this end, he and his group employ modern EPR spectroscopy. Unlike related methods such as nuclear magnetic resonance (NMR) spectroscopy, EPR specifically focuses on unpaired electrons, such as those in the metal centers of enzymes. “The advantage of this technique is that it’s very local and allows us to really zoom in on the reaction site,” explains Cutsail.

For these investigations, Cutsail has access to a newly procured spectrometer which is capable of entirely new temporal resolutions. “We can perform around 2,000 scans per second,” says the chemist with a smile. His aim is to directly track chemical reactions – no longer just analyzing frozen snapshots, but observing intermediate stages in real time. “We want to see the reaction live” – this is his vision. Although this methodology is still being developed, once ready it should afford brand new insights into short-lived catalytic processes.

Cooperation as engine of innovation

EPR spectroscopy is also highly promising for research questions in other disciplines. Cutsail has already forged various partnerships at LMU – for example, he is investigating various materials in cooperation with the e-conversion Cluster of Excellence. “The technology is not limited to biological systems,” he emphasizes. “We can apply it to a wide variety of different materials.”

For him, this is precisely the appeal: “We’re working with groups that manufacture extremely sophisticated samples – often the best in the world – and we bring the spectroscopic tools. This gives rise to new challenges, which in turn drive the development of new techniques – to answer questions that were previously inaccessible.”