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Updated: Sep 24, 2025

Author Spotlight: Photo Switchable Protein Recruitment for Reversible Patterning in Artificial Cellular Systems
Published on: February 23, 2024
Reversible molecular motional switch based on circular photoactive protein oligomers exhibits unexpected
Sang Jin Lee1,2,3, Youngmin Kim1,2,3, Tae Wu Kim1,2
1Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
Abstract:
Molecular switches alterable between two stable states by environmental stimuli, such as light and temperature, offer the potential for controlling biological functions. Here, we report a circular photoswitchable protein complex made of multiple protein molecules that can rapidly and reversibly switch with significant conformational changes. The structural and photochromic properties of photoactive yellow protein (PYP) are harnessed to construct circular oligomer PYPs (coPYPs) of desired sizes. Considering the light-induced N-terminal protrusion of monomer PYP, we expected coPYPs would expand upon irradiation, but time-resolved X-ray scattering data reveal that the late intermediate has a pronounced light-induced contraction motion. This work not only provides an approach to engineering a novel protein-based molecular switch based on circular oligomers of well-known protein units but also demonstrates the importance of characterizing the structural dynamics of designed molecular switches.
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