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

Utana Umezaki,Masahide Terazima,Yusuke Nakasone,Miu Hatakenaka,Yoshifumi Kimura,Kana Onodera,Suhyang Kim,Hiroto Mizutani

doi:10.3390/molecules26154554

Utana Umezaki, Masahide Terazima + Show 6 more

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https://doi.org/10.3390/molecules26154554

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Abstract

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.

Highlights

The interaction between ionic liquids (ILs) and proteins has attracted significant interest
They analyzed the state of dissolved cytochrome C in Hy[ch][dhp] by resonance Raman spectroscopy and FT-IR spectroscopy and found that the structure of the protein did not change in Hy[ch][dhp]
ResIunlttshe present study, we demonstrate how the photocycle of a protein is modified by Hy[ch][dhp]

Summary

Introduction

The interaction between ionic liquids (ILs) and proteins has attracted significant interest. Cytochrome C could be stored in a mixture of water and [ch][dhp] (Hy[ch][dhp]) for more than 18 months without denaturation. They analyzed the state of dissolved cytochrome C in Hy[ch][dhp] by resonance Raman spectroscopy and FT-IR spectroscopy and found that the structure of the protein did not change in Hy[ch][dhp]. The effect of ILs on protein refolding has been discussed in relation to the stability of the proteins in HyILs [9,10,11,12]. ILs with long alkyl chains such as 1-decyl-3-methylimidazolium chloride can induce the refolding of cytochrome C after denaturation by urea and guanidine hydrochloride [11].

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