fulltext.study @t Gmail

Absorption and emission spectroscopic characterization of photo-dynamics of photoactivated adenylyl cyclase mutant bPAC-Y7F of Beggiatoa sp.

Paper ID Volume ID Publish Year Pages File Format Full-Text
29944 44448 2014 12 PDF Available
Title
Absorption and emission spectroscopic characterization of photo-dynamics of photoactivated adenylyl cyclase mutant bPAC-Y7F of Beggiatoa sp.
Abstract

•Mutation changes singlet BLUF domain photo-cycle to triplet based photo-dynamics.•Three conformations of SUMO-bPAC-Y7F with different photo-dynamics are observed.•First fraction follows triplet based flavin semiquinone photo-cycle dynamics.•Second fraction forms irreversible flavin hydroquinone charge transfer complex.•Third fraction undergoes blue-light induced reversible flavin-C4a adduct formation.

The photoactivated cyclase bPAC of the microbial mats bacterium Beggiatoa sp. consists of a BLUF domain and an adenylyl cyclase domain. It has strong activity of photo-induced cyclic adenylyl monophosphate (cAMP) formation and is therefore an important optogenetic tool in neuroscience applications. The SUMO-bPAC-Y7F mutant where Tyr-7 is replaced by Phe-7 in the BLUF domain has lost the typical BLUF domain photo-cycle dynamics. Instead, the investigated SUMO-bPAC-Y7F mutant consisted of three protein conformations with different triplet based photo-dynamics: (i) reversible flavin quinone (Fl) cofactor reduction to flavin semiquinone (FlH), (ii) reversible violet/near ultraviolet absorbing flavin photoproduct (FlA) formation, and (iii) irreversible red absorbing flavin photoproduct (FlC) formation. Absorption and emission spectroscopic measurements on SUMO-bPAC-Y7F were carried out before, during and after light exposure. Flavin photo-dynamics schemes are developed for the SUMO-bPAC-Y7F fractions performing photo-induced FlH, FlA, and FlC formation. Quantitative parameters of the flavin cofactor excitation, relaxation and recovery dynamics in SUMO-bPAC-Y7F are determined.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Photoactivated cyclase bPAC; BLUF domain; Soil bacterium Beggiatoa sp.; Triplet based flavin semiquinone photo-cycle; Flavin-C4a-adduct photo-cycle; Anionic flavin hydoquinone charge transfer complex formation
First Page Preview
Absorption and emission spectroscopic characterization of photo-dynamics of photoactivated adenylyl cyclase mutant bPAC-Y7F of Beggiatoa sp.
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 140, November 2014, Pages 182–193
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us