Our current research focuses can be divided into four segments:
These research themes signify our aspiration to combine our discoveries and fundamental knowledge in enzymes and metabolic pathways with our mission to conduct research that supports developments in the areas of circular economy (CO2 utilization), biohydrogen production, green chemistry, food safety, biosensors and bioimaging.
Overview of current research in Chaiyen’s group
Chaiyen’s group – Supporting developments in the area of circular economy
Enzyme structures and mechanismsEnzymes are catalysts that are vital for all organisms to maintain their cellular activities. Understanding enzyme reaction mechanisms has tremendous significance in technology development.
Our research group has long been recognized for pioneering work in the discovery of reaction mechanisms of flavin-dependent, redox and aldolase enzymes. We use a multi-disciplinary approach and a wide range of physical and biochemical tools and techniques such as transient kinetics, spectroscopy, structural biology and computational chemistry for studying enzymatic reactions.
Currently, our group studies reaction mechanisms of selected flavin-dependent monooxygenases, halogenases, dehalogenases and oxidases, electron transfer flavoenzymes, P450 enzymes and firefly luciferases. We have identified challenging questions and gap of knowledge in these enzymatic systems which should be tackled by mechanistic enzymology approach. Fundamental knowledge gained from studying these enzymatic systems will also be combined with development in application application proposes to obtain useful innovations in the future.
Picture illustrating diverse catalysis by a common C4a-(hydro)peroxyflavin in flavin-dependent monooxygenase.
(Reference: Phintha A. and Chaiyen P. Journal of Biological Chemistry, in press)
Selected recent publications
Biocatalysis is the use of enzymes in synthesis of valuable chemicals. The chemicals industry is under pressure to conserve energy, reduce CO2 emissions and minimize toxic waste so as to reduce environmental damage. Biocatalysis is the use of enzymatic reactions in the forms of isolated enzymes or in whole cells to catalyze chemical reactions. The use of enzymatic reactions in chemical production can contribute to greener and cleaner industries. With the catalytic power of enzymes, processes can be operated under mild pH and temperature and without creation of hazardous intermediates and waste.
Our group leverages our in-depth understanding of enzymatic mechanisms to improve enzymatic properties via enzyme engineering approach. We are well equipped with robotic high-throughput liquid handing and high-resolution mass spectrometry systems which allow us to perform cutting-edge enzyme engineering work. This semi-rational or mechanism-guided approach has resulted in successful development of efficient and robust enzymes and biocatalysts that meet industrial standards.
Currently, our group studies engineering and biocatalysis of several flavin-dependent, P450 and other redox enzymes. These enzymes are attractive for green chemistry applications such as for synthesis active pharmaceutical ingredients or valuable bioactive compounds. Biocatalytic reactions are considered as green technology for the future because the process does not require high energy, harsh conditions or toxic chemicals.
Use of mechanism-guided approach to improve catalytic properties of a flavin-dependent halogenase
(Reference: Prakinee K, Phintha A, et al. Nat Catal 2022 Jun;5:534-44)
Selected recent publications
Synthetic biology is the design and construction of new biological entities such as enzymes, genetic circuits, and cells or the redesign of existing biological systems. Research in this field is multidisciplinary by nature and employs an engineering approach to construct and put together new or engineered biomolecular units such enzymes, genetic circuits, metabolic pathways, etc. In general, the assembly of these biomolecular parts and devices is performed to solve specific problems or accomplish specific goals.
Synthetic biology projects in our group employ state-of-the-art technology to construct engineered cells and new metabolic pathways via metabolic engineering approach for turning low value feedstock such as sugar, CO2 and bio-wastes such as lignocellulosic biomass and triglyceride into value-added products. Recently, we have developed a promising cell prototype which can significantly enhance the amount of biohydrogen production. We are collaborating with leading industrial partners to develop cell prototypes which can be used in industrial scale production of valuable compounds from low value feedstocks. We believe that technology development in this research area and partnership with private sector are important for making industrial processes more sustainable and mitigating environmental damage and climate change.
Current work theme in Synthetic Biology area in Chaiyen’s group.
Selected recent publications
Nature is smart and beautiful, and we harness its power in finding elegant solutions to practical problems. Some of the enzymatic reactions studied by our group can generate signals such as light or electrical output. These reactions can be linked to detection of specific molecules including genes related to diseases or pesticide contaminants in the environment and food produce.
We have developed bioreporting technologies based on enzymatic reactions of luciferases or enzymes that can emit blue, green or orange light. These reactions can be used as in vivo cell monitoring tools for specific gene or disease detection in experimental animals. Our group also has developed a new enzymatic cascade reaction for the synthesis of luciferin analogs from phenolic compounds, (HELP reaction). Luciferin is the substrate of the enzyme luciferase and causes fireflies to glow. Bioluminescence catalyzed by luciferase is an important method used in biochemical research and the analysis of toxitoxicantsns. HELP makes it possible to produce luciferin analogs much more easily than before, without special expertise or toxic chemicals. Our team also produced two novel luciferin analogs. One of these produces brighter light of a longer wavelength than the original, which penetrates cells and tissues more efficiently. This facilitates real-time imaging and helps to reduce animal experiments.
Our group has also invented a proprietary, enzymatic reaction-based method named LUMOS (LUminescence-related Measurement Of Specific Detection) to detect and degrade pesticides in one-pot system. The overuse of toxic organophosphate pesticides (OPs) is a serious global environmental and health problem. It affects farmers who work the toxic land and consumers who eat the toxic produce. Toxic pesticide residues also contaminate ground water and water reservoirs, and have been linked to cancer, Alzheimer’s, and diabetes. LUMOS works in three reaction steps:
LUMOS technology can degrade pesticides and convert them into luciferin derivatives. By adding the enzyme luciferase, the systems generate light emission for pesticide detection.
References: Watthaisong P et al. Angew Chem Int Ed Engl. 2019 Sep;58(38):13254-13258.
Watthaisong P et al. Angew Chem Int Ed Engl 2022 Apr;61(16):e202116908.
Selected recent publications