Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1

The retinal photocycle dynamics of the fluorescent voltage sensor QuasAr1 (Archaerhodopsin 3 P60S-T80S-D95H-D106H-F161V mutant from Halorubrum sodomense) in pH 8 Tris buffer was studied. The samples were photoexcited to the first absorption band of the protonated retinal Schiff base (PRSB) Ret_580 (...

Descripción completa

Detalles Bibliográficos
Autores principales: Penzkofer, Alfons, Silapetere, Arita, Hegemann, Peter
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982170/
https://www.ncbi.nlm.nih.gov/pubmed/31881701
http://dx.doi.org/10.3390/ijms21010160
_version_ 1783491253702230016
author Penzkofer, Alfons
Silapetere, Arita
Hegemann, Peter
author_facet Penzkofer, Alfons
Silapetere, Arita
Hegemann, Peter
author_sort Penzkofer, Alfons
collection PubMed
description The retinal photocycle dynamics of the fluorescent voltage sensor QuasAr1 (Archaerhodopsin 3 P60S-T80S-D95H-D106H-F161V mutant from Halorubrum sodomense) in pH 8 Tris buffer was studied. The samples were photoexcited to the first absorption band of the protonated retinal Schiff base (PRSB) Ret_580 (absorption maximum at λ(max) ≈ 580 nm), and the retinal Schiff base photoisomerization and protonation state changes were followed by absorption spectra recordings during light exposure and after light exposure. Ret_580 turned out to be composed of two protonated retinal Schiff base isomers, namely Ret_580(I) and Ret_580(II). Photoexcitation of Ret_580(I) resulted in barrier-involved isomerization to Ret_540 (quantum yield ≈ 0.056) and subsequent retinal proton release leading to Ret_410 deprotonated retinal Schiff base (RSB). In the dark, Ret_410 partially recovered to Ret_580(I) and partially stabilized to irreversible Ret_400 due to apoprotein restructuring (Ret_410 lifetime ≈ 2 h). Photoexcitation of Ret_580(II) resulted in barrier-involved isomerization to Ret_640 (quantum yield ≈ 0.00135) and subsequent deprotonation to Ret_370 (RSB). In the dark, Ret_370 partially recovered to Ret_580(II) and partially stabilized to irreversible Ret_350 due to apoprotein restructuring (Ret_370 lifetime ≈ 10 h). Photocycle schemes and reaction coordinate diagrams for Ret_580(I) and Ret_580(II) were developed and photocyle parameters were determined.
format Online
Article
Text
id pubmed-6982170
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-69821702020-02-07 Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1 Penzkofer, Alfons Silapetere, Arita Hegemann, Peter Int J Mol Sci Article The retinal photocycle dynamics of the fluorescent voltage sensor QuasAr1 (Archaerhodopsin 3 P60S-T80S-D95H-D106H-F161V mutant from Halorubrum sodomense) in pH 8 Tris buffer was studied. The samples were photoexcited to the first absorption band of the protonated retinal Schiff base (PRSB) Ret_580 (absorption maximum at λ(max) ≈ 580 nm), and the retinal Schiff base photoisomerization and protonation state changes were followed by absorption spectra recordings during light exposure and after light exposure. Ret_580 turned out to be composed of two protonated retinal Schiff base isomers, namely Ret_580(I) and Ret_580(II). Photoexcitation of Ret_580(I) resulted in barrier-involved isomerization to Ret_540 (quantum yield ≈ 0.056) and subsequent retinal proton release leading to Ret_410 deprotonated retinal Schiff base (RSB). In the dark, Ret_410 partially recovered to Ret_580(I) and partially stabilized to irreversible Ret_400 due to apoprotein restructuring (Ret_410 lifetime ≈ 2 h). Photoexcitation of Ret_580(II) resulted in barrier-involved isomerization to Ret_640 (quantum yield ≈ 0.00135) and subsequent deprotonation to Ret_370 (RSB). In the dark, Ret_370 partially recovered to Ret_580(II) and partially stabilized to irreversible Ret_350 due to apoprotein restructuring (Ret_370 lifetime ≈ 10 h). Photocycle schemes and reaction coordinate diagrams for Ret_580(I) and Ret_580(II) were developed and photocyle parameters were determined. MDPI 2019-12-25 /pmc/articles/PMC6982170/ /pubmed/31881701 http://dx.doi.org/10.3390/ijms21010160 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Penzkofer, Alfons
Silapetere, Arita
Hegemann, Peter
Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
title Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
title_full Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
title_fullStr Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
title_full_unstemmed Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
title_short Photocycle Dynamics of the Archaerhodopsin 3 Based Fluorescent Voltage Sensor QuasAr1
title_sort photocycle dynamics of the archaerhodopsin 3 based fluorescent voltage sensor quasar1
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982170/
https://www.ncbi.nlm.nih.gov/pubmed/31881701
http://dx.doi.org/10.3390/ijms21010160
work_keys_str_mv AT penzkoferalfons photocycledynamicsofthearchaerhodopsin3basedfluorescentvoltagesensorquasar1
AT silapeterearita photocycledynamicsofthearchaerhodopsin3basedfluorescentvoltagesensorquasar1
AT hegemannpeter photocycledynamicsofthearchaerhodopsin3basedfluorescentvoltagesensorquasar1