Initial photophysical characterization of the proteorhodopsin optical proton sensor (PROPS)
- Creators
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Nadeau, Jay L.
Abstract
Fluorescence is not frequently used as a tool for investigating the photocycles of rhodopsins, largely because of the low quantum yield of the retinal chromophore. However, a new class of genetically encoded voltage sensors is based upon rhodopsins and their fluorescence. The first such sensor reported in the literature was the proteorhodopsin optical proton sensor (PROPS), which is capable of indicating membrane voltage changes in bacteria by means of changes in fluorescence. However, the properties of this fluorescence, such as its lifetime decay components and its origin in the protein photocycle, remain unknown. This paper reports steady-state and nanosecond time-resolved emission of this protein expressed in two strains of Escherichia coli, before and after membrane depolarization. The voltage-dependence of a particularly long lifetime component is established. Additional work to improve quantum yields and improve the general utility of PROPS is suggested.
Additional Information
© 2015 Nadeau. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Received: 24 June 2015; Accepted: 21 August 2015; Published: 04 September 2015. This work was performed in the laboratory of Stephen Bradforth at USC. JN's salary support was provided by the Canada Research Chairs. Thanks to J. Lanyi for useful discussions. Conflict of Interest Statement: The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.Attached Files
Published - fnins-09-00315.pdf
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Additional details
- PMCID
- PMC4559597
- Eprint ID
- 61482
- Resolver ID
- CaltechAUTHORS:20151023-103340173
- Canada Research Chairs
- Created
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2015-10-26Created from EPrint's datestamp field
- Updated
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2022-05-23Created from EPrint's last_modified field