Two-Photon Conversion of a Bacterial Phytochrome


In nature, sensory photoreceptors underlie diverse spatiotemporally precise and generally reversible biological responses to light. Photoreceptors also serve as genetically encoded agents in optogenetics to control by light organismal state and behavior. Phytochromes represent a superfamily of photoreceptors that transition between states absorbing red light (Pr) and far-red light (Pfr), thus expanding the spectral range of optogenetics to the near-infrared range. Although light of these colors exhibits superior penetration of soft tissue, the transmission through bone and skull is poor. To overcome this fundamental challenge, we explore the activation of a bacterial phytochrome by a femtosecond laser emitting in the 1 μm wavelength range. Quantum chemical calculations predict that bacterial phytochromes possess substantial two-photon absorption cross sections. In line with this notion, we demonstrate that the photoreversible Pr↔Pfr conversion is driven by two-photon absorption at wavelengths between 1170 and 1450 nm. The Pfr yield was highest for wavelengths between 1170 and 1280 nm and rapidly plummeted beyond 1300 nm. By combining two-photon activation with bacterial phytochromes, we lay the foundation for enhanced spatial resolution in optogenetics and unprecedented penetration through bone, skull and soft tissue.

Publication DOI:
Divisions: College of Engineering & Physical Sciences > Aston Institute of Photonics Technology (AIPT)
College of Engineering & Physical Sciences
Additional Information: © 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Uncontrolled Keywords: Biophysics
Publication ISSN: 1542-0086
Last Modified: 28 May 2024 07:20
Date Deposited: 16 Mar 2021 15:03
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Related URLs: https://www.sci ... 006349521000874 (Publisher URL)
http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2021-03-02
Published Online Date: 2021-02-02
Accepted Date: 2021-01-07
Authors: Sokolovski, Serge G.
Zherebtsov, Evgeny A.
Kar, Rajiv K.
Golonka, David
Stabel, Robert
Chichkov, Nikolai B.
Gorodetsky, Andrey
Schapiro, Igor
Möglich, Andreas
Rafailov, Edik U. (ORCID Profile 0000-0002-4152-0120)

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