Strong pH-dependent near-infrared fluorescence in a microbial rhodopsin reconstituted with a red-shifting retinal analogue

0522223 - FZÚ 2020 RIV US eng J - Journal Article
Hontani, Y. - Ganapathy, S. - Frehan, S. - Kloz, Miroslav - de Grip, W.J. - Kennis, J.T.M.
Strong pH-dependent near-infrared fluorescence in a microbial rhodopsin reconstituted with a red-shifting retinal analogue.
Journal of Physical Chemistry Letters. Roč. 9, č. 22 (2018), s. 6469-6474. ISSN 1948-7185
R&D Projects: GA MŠMT EF15_003/0000449
Grant - others:OP VVV - HiFi(XE) CZ.02.1.01/0.0/0.0/15_003/0000449
Institutional support: RVO:68378271
Keywords : photochemical-reaction cycle * ion-pump rhodopsin * resonance Raman * all-trans * vibrational analysis * femtosecond * chromophore * dynamics * spectroscopy
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 7.329, year: 2018
Method of publishing: Open access

Near-infrared (NIR)-driven rhodopsins are of great interest in optogenetics and other optobiotechnological developments such as artificial photosynthesis and deep-tissue voltage imaging. Here we report that the proton pump proteorhodopsin (PR) containing a NIR-active retinal analogue (PR:MMAR) exhibits intense NIR fluorescence at a quantum yield of 3.3%. This is 130 times higher than native PR (Lenz, M. O. et al. Biophys J. 2006, 91, 255-262) and 3-8 times higher than the QuasAr and PROPS voltage sensors (Kralj, J., et al. Science 2011, 333, 345-348, Hochbaum, D. R et al. Nat. Methods 2014, 11, 825-833). The NIR fluorescence strongly depends on the pH in the range of 6-8.5, suggesting potential application of MMAR-binding proteins as ultrasensitive NIR-driven pH and/or voltage sensors. absorption spectroscopy showed that upon near-IR excitation, PR:MMAR features an unusually long 310 ps and the absence of isomerized photoproducts, consistent with the high fluorescence quantum yield.
Permanent Link: http://hdl.handle.net/11104/0306741