Enzymes drive reactions that enable life. Einstein Visiting Fellow Professor Wonwoo Nam is researching how metalloenzymes produce oxygen through photosynthesis and how they are used in the body for various vital reactions. This basic knowledge is crucial for the transition towards a green chemistry.
The oxygen we inhale is bound by the iron ion to the active core of hemoglobin in our red blood cells. The hemoglobin proteins also carry the molecular oxygen to the cells of our body, where it is activated by specific metalloenzymes.
I am trying to understand how such metalloenzymes, which contain metals such as iron, copper, or manganese in their active cores, act as catalysts to activate the dioxygen and produce chemical molecules in our bodies that we need for various metabolic activities. I also study how metalloenzymes produce dioxygen from water during photosynthesis. Both processes, the activation of dioxygen and its formation, are fundamental chemical reactions. Understanding this chemistry at the heart of life is the goal of bioinorganic research.
We carry out this fundamental research to be able to design artificial metalloenzymes that can act as effective catalysts for the synthesis of specific chemicals for industry. If humans want to travel to the moon or to Mars, they will need dioxygen. If water is available, artificial enzymes could help to catalyse water into dioxygen to enable humans to breathe. They could act as life enablers, just as they do in biological processes.
There is a very long history of research exploring the activation and formation of dioxygen. We have long known that enzymes activate dioxygen in cells. But we are still finding new enzymes that are involved in the reaction. The same is true of dioxygen formation. We have known about the chemical reaction that produces dioxygen from water for about 100 years, but we still do not know exactly how the oxygen-oxygen bond in dioxygen is formed.
For me, seeing is believing. In the past, we have been unable to observe the reactive intermediates of dioxygen activation and formation, so many researchers just assumed they were there. My expertise is to make them visible and to isolate them in order to understand their activity more clearly. In my research over the last two decades, I have discovered some important intermediates involved in dioxygen activation and formation reactions. One highlight is a Science paper published in 2003 together with Professor Lawrence Que Jr. from the University of Minnesota, in which we showed that a non-heme enzyme forms an iron-oxygen intermediate upon dioxygen activation. I believe this finding opened up a new field in bioinorganic chemistry.
In my eyes, enzymes are smarter than humans because they have evolved over billions of years and know how to handle all chemical reactions. That is amazing. Will we humans be able to recreate all their reactions? We hope so, but we are hardly close. Probably, over the next 30 to 50 years we will keep working on dioxygen chemistry. It might even turn out to be a never-ending story.
If artificial photosynthesis works one day, it will change everything. Basically, it will solve all of our energy problems. We will no longer need to use fossil fuels. We could use water instead, avoiding air pollution and CO2 production. Cars are running on hydrogen already and we are able to convert water into dioxygen and hydrogen using artificial catalysts. However, the cost of production is still too high. The ability to use free solar energy through artificial photosynthesis could make this process much cheaper and commercially viable.
In Berlin, my collaborator Professor Kallol Ray is an expert in spectroscopy. He has the specific know-how to characterize the intermediates of bioinorganic reactions and to design artificial catalysts. Combining this with my expertise in synthesizing intermediates and studying their kinetics and reactivities, we will be able to significantly advance our knowledge of oxygen activation and formation. Together, we will synthesize artificial enzymes and observe their reactions using spectroscopy and artificial intelligence to understand our observations.
Bioinorganic chemistry is the key to understanding the chemistry that occurs in our bodies. Using this inspiration from nature to develop green chemistry can help us to make life better – inside and outside.