Effect of Hydrated Ionic Liquid on Photocycle and Dynamics of Photoactive Yellow Protein

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 15; p. 4554
• Main Authors: Umezaki, Utana, Hatakenaka, Miu, Onodera, Kana, Mizutani, Hiroto, Kim, Suhyang, Nakasone, Yusuke, Terazima, Masahide, Kimura, Yoshifumi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 28.07.2021; MDPI
• Subjects: Absorption spectroscopy; Buffer solutions; Choline; conformational change; Cytochrome; Diffusion coefficient; hydrated ionic liquid; Ionic liquids; Photoactive yellow protein; photocycle; Photoexcitation; Protein structure; Proteins; Secondary structure; Spectrum analysis; transient grating spectroscopy; Yellow protein
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26154554

The mechanism by which proteins are solvated in hydrated ionic liquids remains an open question. Herein, the photoexcitation dynamics of photoactive yellow protein dissolved in hydrated choline dihydrogen phosphate (Hy[ch][dhp]) were studied by transient absorption and transient grating spectroscopy. The photocyclic reaction of the protein in Hy[ch][dhp] was similar to that observed in the buffer solution, as confirmed by transient absorption spectroscopy. However, the structural change of the protein during the photocycle in Hy[ch][dhp] was found to be different from that observed in the buffer solution. The known change in the diffusion coefficient of the protein was apparently suppressed in high concentrations of [ch][dhp], plausibly due to stabilization of the secondary structure.