PeerJ Award Winner: ICBIC20

The Twentieth International Conference on Biological Inorganic Chemistry (ICBIC20) was held at the Adelaide Convention Centre in Adelaide, Australia from July 16 to 21. Held in parallel with the Royal Australian Chemical Institute’s Inorganic Division National conference, the ICBIC20 covered all aspects of the molecular roles of metal ions in human health and disease and in the pharmaceutical and imaging sciences, as well as connections to related fields such as environmental and nutrition sciences.

PeerJ Inorganic Chemistry sponsored two awards for the best posters presented at the conference. We recently spoke to one of the award winners, Yuya Yokoyama, about his research.

Yuya Yokoyama

PhD student at Nagoya University, Japan.

Can you tell us a bit about yourself and your research interests?

I am Yuya Yokoyama, a PhD student in Graduate School of Science at Nagoya University. I belong to the bioinorganic chemistry laboratory (Prof. Shoji’s group). My research interest is tricking and engineering natural metalloenzymes (especially cytochrome P450 enzymes) for reactions of non-native substrates with natural molecules activating enzymes and directed evolution.

What first interested you in this field of research?

Before I focused this field of research, I was interested in general organic chemistry and green chemistry. When I was an undergraduate student, some lectures by Prof. Shoji interested me in enzyme chemistry and its application to bioconversion. Enzymes can catalyze various reactions in mild conditions (for example, in an aqueous solution, at room temperature, or at standard pressure). I felt that these characteristics are more interesting for me than some organic or organometallic catalysts and I wanted to engineer and investigate enzymes for the application of bioconversion.

Can you briefly explain the research you presented at ICBIC20?

Our research group has discovered that synthetic dummy substrates, called “decoy molecules”, induce reactions of non-native substrates by cytochrome P450BM3. Moreover, we recently reported whole-cell hydroxylation of benzene with decoy molecules by P450BM3. However, most of the developed decoy molecules are ineffective at the whole-cell reaction due to their low permeability through cell membranes. In my research, I focus on a type of natural product, acyl homoserine lactone (HSL), which is known as a bacterial communication molecule, and I tried to engineer P450BM3 mutants to accept HSL as a decoy molecule. As a strategy for engineering mutants, I adopted directed evolution and proceeded five rounds of evolution. The evolved mutant shows high catalytic activity in the presence of HSL in the hydroxylation of benzene and other non-native substrates. Therefore, we successfully engineered P450BM3 mutants utilizing effective decoy molecules for whole-cell hydroxylation of non-native substrates.

What are your next steps?

Currently, I am working on reactions related to green chemistry with the developed P450BM3 mutants by leveraging the advantage of C10-HSL as a natural product. In the future, I want to introduce some functional groups into decoy molecule and engineer P450BM3 mutants accepting these molecules for further challenging reactions.

Fumiya Ito

PhD student at Nagoya University, Japan.

Can you tell us a bit about yourself and your research interests?

My name is Fumiya Ito, a PhD student in the Graduate School of Science at Nagoya University. I have always been interested in controlling enzyme functions including tricking metalloenzymes using dummy substrates. During my master’s studies, I focused on environmental applications of this unique reaction system. Currently, I am working on predictive modelling of the enzymatic reactions activated by the dummy substrates.

What first interested you in this field of research?

I was once interested in other research fields, but became completely fascinated by the designability and flexibility of proteins which allow a broad range of application. Also, excellent catalytic activities exhibited by metal complexes grabbed my interest at around the same time. During my undergraduate years, I met my current supervisor Prof. Dr. Osami Shoji and got interested in bioinorganic chemistry. Bioinorganic chemistry is where those two fields (biochemistry and inorganic chemistry) were mixed, hence I decided to start working in this field.

Can you briefly explain the research you presented at ICBIC20?

One solution to combat soil contamination is bioaugmentation, which is addition of cultured microorganisms to decompose contaminants. However, there is a limit to the usable bacterial species because it is necessary to avoid negative impacts on nearby ecosystems. For example, we should not use genetically modified organisms in open systems. As Mr. Yokoyama mentioned above, our group developed a unique reaction system using dummy substrates called “decoy molecules”. Cytochrome P450 enzymes catalyzes non-native reactions through substrate misrecognition. Moreover, the decoy molecules can also induce whole-cell reactions in recombinant E. coli. In my research, I obtained several bacterium-decoy molecule pairs suitable for hydroxylation of aromatic compounds among 12 naturally occurring (genetically unmodified) bacteria and dozens of decoy molecules. This suggested that the decoy molecules can activate microorganisms as bioaugmentation tools without genetic modification.

What are your next steps?

I am interested in whether the substrate misrecognition also occurs in nature. To reveal that, I want to obtain natural products that can control naturally occurring microorganisms by functioning as decoy molecules. Moreover, I am currently working on predictive modelling of the reaction system using in vitro reaction data. I hope that I will be able to combine the two research topics in the future.