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Chemical Biology Seminar: Professor Yifan Dai, Washington University in St. Louis

Yifan Dai
Date
Tue February 4th 2025, 3:00 - 4:00pm
Location
Sapp Center Lecture Hall 114

About the Seminar 

Lightning Phases and Surfaces: Intracellular electrochemistry powered by phase transition

Phase transitions driven by multivalent biomacromolecules, such as intrinsically disordered proteins, have emerged as a critical organizational strategy in living cells. This transition process results in phase separation and forms membraneless structures known as biomolecular condensates. A key conundrum in condensate research is why such a second phase is necessary for cellular functions, as the same effects of sequestration, exclusion and enrichment generated by a phase separated condensate can also be achieved through the formation of stoichiometric macromolecular assemblies and the phase transition process is thermodynamically costly. In this talk, I will untangle this conundrum by presenting examples that illustrate how the phase transition of biomacromolecules leads to a density transition of the entire solution system (the cellular matrix), governed by electrochemical potential equilibrium. This transition process generates an ion density gradient between phases, encoding an electric potential gradient between phases. I will show how the formation of this potential gradient can alter cellular electrochemical potential equilibria, presenting an intracellular strategy on regulating cellular electrochemistry. I will further demonstrate how the formation of a second phase delivers electrochemically active surfaces. Coupled with the potential gradient set up by the phase transition process, the biological surfaces of condensates or biomacromolecular assemblies encode interfacial electric field that can power diverse chemical reactions. These inherent electrochemical functions of biological assemblies reveal a non-enzymatic strategy of living cells on modulating cellular chemical homeostasis, potentially leading to disease progression. Overall, our works present a new paradigm for understanding cellular functioning mechanisms and intracellular electrochemistry.

About the Speaker

Professor Yifan Dai is an Assistant Professor in the Department of Biomedical Engineering and the Center for Biomolecular Condensates at Washington University in St. Louis. Yifan received his B.S. (2017) and Ph.D. (2020) in Chemical and Biomolecular Engineering from Case Western Reserve University, working with Prof. Chung Chiun Liu and Prof. Arnold Caplan on interfacing electrochemistry with synthetic biology. During his undergraduate and doctoral research, he focused on developing sensors and biosensors that have been applied in industrial and medical settings. In 2020, he joined Duke University as a postdoctoral scholar, jointly advised by Prof. Tosh Chilkoti and Prof. Lingchong You, where he worked on designing synthetic protein materials for cellular controls. In 2023, he joined Washington University in St. Louis as an Assistant Professor. His research group works at the interface of physical chemistry and biology, focusing on establishing the mechanisms of intracellular electrochemistry and developing synthetic biomolecules for manipulating cellular organizations. He was recently recognized by the Forbes 30 under 30 2025.

Host: Dick Zare