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Sub-THz waves accelerate microscopic mixing of water and protein molecules

Proteins are biomolecules that perform mechanical and chemical works. In order to apply their functions, it is necessary to better understand their physical and chemical mechanisms. However, understanding these mechanisms is not easy because collective interactions between protein and the surrounding water molecules (i.e., hydration) are complex. Dr. Imashimizu and his research group have successfully observed that externally applied sub-THz electromagnetic fields perturb the rapid collective dynamics in protein-water systems. For this observation, they developed a highly sensitive dielectric relaxation measurement technique under sub-THz irradiation and evaluated the collective dynamics of water molecules networked by hydrogen bonds. They further verified the relevance of this observation with NMR and terahertz spectroscopies. They found that a protein hydration change, which usually take a long time, is significantly accelerated by sub-THz irradiation. This finding suggests that the hydration phenomenon, which is essential for the expression of protein functions, could be regulated by sub-THz irradiation. This result is a new insight into protein hydration, and is expected to contribute to the activation of enzymatic reactions, techniques for preserving and aging food and beverages etc. in the future.

Research group


  • Masahiko Imashimizu (Applied Molecular Function Research Group)
  • Jun-ichi Sugiyama (Nanomaterials Research Institute)
  • Masahito Tanaka & Daisuke Satoh(Research Institute for Measurement and Analytical Instrumentation)

Other institutions

  • Yuji Tokunaga & Koh Takeuchi (Univ Tokyo)
  • Mafumi Hishida (Univ Tsukuba, Currently Tokyo Univ. Science)

Shortly after mixing water and dehydrated protein, hydrogen bonding network in hydration water is partially broken (left). Subsequently, a stable hydration structure is slowly formed by removing strong bonds with electric charges and recombining the network (right). Sub-THz irradiation would shorten the time required for this change. Positive charges on amino acid side chains are indicated by +, and intermolecular interaction and ion-molecular-interaction are indicated by ・・・

hydrogen bonding network


  • Title:Nonthermal acceleration of protein hydration by sub-terahertz irradiation.
  • Authors:Jun-ichi Sugiyama#, Yuji Tokunaga#, Mafumi Hishida#, Masahito Tanaka, Koh Takeuchi, Daisuke Satoh, Masahiko Imashimizu*
    #Contributed equally、*Corresponding author
  • Journal:Nature Communications, 2023. 14:2825

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