Presentation Information
[3D11]Quantifying overpotential-induced heat in redox enzymes toward bioinspired catalyst design
*Kakeru Sekiguchi1, Kaito Homma2, Kenji Hayashida1, Lu Bang3, Satoru Takakusagi3, Kotaro Takeyasu3 (1. Graduate School of Science and Technology, University of Tsukuba, 2. Graduate School of Environmental Science, Hokkaido University, 3. Institute for Catalysis, Hokkaido University)
Enzymes are highly efficient and selective catalysts, expected to contribute to sustainable technologies. However, their structural complexity and low stability limit industrial use. This study aims to clarify the mechanisms of electron transfer and heat generation in enzymatic redox reactions to guide the design of artificial catalysts. We focus on mixed potentials formed between multiple electron donors and acceptors, which may cause overpotential contributing to reaction driving force—an aspect rarely studied. In contrast to thermochemical reactions with fixed enthalpy, heat per molecule in mixed-potential systems varies with substrate concentration, reflecting changes in overpotential. To evaluate this, we developed a custom measurement system using a Peltier device to detect heat as voltage. The system’s resolution was validated with yeast respiration, which produced measurable thermal signals. This setup will be applied to assess heat generation in enzymatic reactions.