Wired In: Yi Lu

Wired In: Yi Lu

Each week, staff writer Paul Wood profiles a high-tech leader. This week, meet Professor YI LU, a chemistry researcher at the University of Illinois. His team has found a novel way to help clean up contaminants that are destroying our environment, as laid out in their report published in the journal Science. He also has something to say about surfing.

How have you work out a method to convert sulfites, which interfere with the elimination of more toxic compounds, to sulfides, which have beneficial uses in industry and health?

The conversion of sulfite to sulfide has been a major challenge, because it is a very difficult problem that scientists have not been able to find a solution to. This is despite a lot of efforts. We solved this problem by looking for inspiration from nature, as bacteria have evolved enzymes millions of years ago to use sulfite (instead of oxygen) for energy production. The key to the solution is an enzyme called sulfite reductase.

What does this enzyme do?

It contains a very complex active center that has puzzled scientists for many years about how it works. We built an artificial enzyme in the laboratory by incorporating key structural features necessary to drive the conversion and improve the activity to a level similar to that of the natural enzyme. Through the process, we have identified and demonstrated what it takes to build a highly efficient catalyst for this important redox reaction.

What is a redox reaction?

"Redox" is a commonly abbreviated word for reduction/oxidation reaction that involves of movement of electrons. A common oxidation reaction is the burning of fuels in air, as oxygen is an "oxidant"; a common reduction reaction is taking vitamin C to prevent oxidative damage in our body, as vitamin C is a "reductant." Redox reactions are common in our lives, including photosynthesis and respiration. Sulfite to sulfide is another example.

Who else is on your team, and what are their contributions?

The majority of the work was performed by graduate students in my group at the University of Illinois. The first author, Evan Mirts, was responsible for most of the design and experimental work, with Parisa Hosseinzadeh helping with the initial design and Igor Petrik with computational work to select our scaffold protein. In addition, Dr. Mark Nilges of the UI contributed to spectroscopic analysis.

What inspired you to work on improving the environment?

Human activity has a profound impact on the environment, and much of that impact comes from the byproducts of industrial processes. Nitrate, perchlorate, arsenate and other similar compounds (called oxyanions) are byproducts from the production of fertilizer, munitions and rocket fuel, and they are especially difficult to remove because they do not bind well to the active metals in most synthetic catalysts. While natural enzymes can play a role in the removal, they are quite expensive and not robust enough for environmental remediation. Synthesizing the artificial enzyme with similar activity as the natural enzyme fills a gap in our knowledge on how to design such a complex enzyme for a very difficult reaction that has eluded to scientists for many years.

Your work on enzymes could improve the quality of petroleum products. What are some of the other uses?

I believe that the knowledge we have gained and the methods we have developed or used in the design process to create our artificial enzyme can be applied and expanded to design new synthetic catalysts or artificial enzymes for a wide variety of other reactions, including nitrogen fixation to make fertilizers under ambient conditions instead of current industrial processes that use high temperature and pressure, as well as solar fuels that generate energy from sunlight and water. Nature uses many of the same tricks to accomplish very difficult reactions that have been challenging to do by scientists, and we are slowly but surely mastering these tricks.

In the future, do you see commercial applications?

The design approach that we used can be used to design or improve new catalysts based on natural enzymes and to improve the activity of enzymes that have been evolved or modified for industrial purposes.

Do you find the simplest approach is often the best one?

Yes and no. Because natural enzymes are quite complex, the simplest approach has been making small molecular models to mimic natural enzymes. While many scientists have been quite successful in using this approach to mimic enzymes containing relatively simple structures that catalyze less-complicated reactions, it becomes increasingly difficult, and in the case of the sulfite-to-sulfide reduction is impossible. We have learned that we need to use a more sophisticated approach to include more structural features than the simple synthetic models can. It is kind of the story of "Goldilocks and the Three Bears": natural enzymes are too complicated; synthetic models are too simple; our approach is just right.

What's your best advice for someone who's starting up?

Catch the next big wave. Good surfers never catch the current big wave when entering the water, as they know they will not be able to ride such a wave for very long or at all. Instead, they go deeper into the ocean and identify the next wave and are prepared to catch it. When such a wave does form, they are on top of it.

Have you ever make any mistakes you've been able to learn from?

More often than I would like to admit. The key is to learn from the failed experiments by carefully analyzing the results to improve the design and develop new methods. Sometimes, failed experiments lead to new discoveries if one does not stop observing, analyzing, redesigning and proving the unexpected results.

Do you have any patents?

We have filed a provisional patent through the Office of Technology Management. We also have a large portfolio of patents on other ways to detect and remove environmental contaminations.

TECH TIDBITS ... from YI LU

Do you have any wearable electronics? I wear a smartwatch that looks like a regular watch with the watch face displayed all the time.

Do you have an entrepreneur hero? Steve Jobs, who is visionary and always ahead of others in developing innovative products.

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