Zirak, P. and Penzkofer, Alfons and Moldt, J. and Pokorny, R. and Batschauer, A. and Essen, L. -O. (2009) Photocycle dynamics of the E149A mutant of cryptochrome 3 from Arabidopsis thaliana. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY, 97 (2). pp. 94-108. ISSN 1011-1344,
Full text not available from this repository. (Request a copy)Abstract
The E149A mutant of the cryDASH member cryptochrome 3 (cry3) from Arabidopsis thaliana was characterized in vitro by optical absorption and emission spectroscopic studies. The mutant protein non-covalently binds the chromophore flavin adenine dinucleotide (FAD). In contrast to the wild-type protein it does not bind N5,N10-methenyl-5,6,7,8-tetrahydrofolate (MTHF). Thus, the photo-dynamics caused by FAD is accessible without the intervening coupling with MTHF. In dark adapted cry3-E149A, FAD is present in the oxidized form (FAD(ox)) semiquinone form (FADH(-)), and anionic hydroquinone form (FAD(red)H(-)). Blue-light photo-excitation of previously unexposed cry3-E149A transfers FAD(ox) to the anionic semiquinone form (FAD(.-)) with a quantum efficiency of about 2% and a back recovery time of about 10 s (photocycle I). Prolonged photo-excitation leads to an irreversible protein re-conformation with structure modification of the U-shaped FAD and enabling proton transfer. Thus, a change in the photocycle dynamics occurs with photo-conversion of FAD x to FADH(-), FADH(-) to FAD(red)H(-), and thermal back equilibration in the dark (photocycle H). The photocycle dynamics of cry3-E149A is compared with the photocycle behaviour of wild-type cry3 and other photo-sensory cryptochromes. (C) 2009 Elsevier B.V. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | FLUORESCENCE SPECTROSCOPIC CHARACTERIZATION; FLAVIN ADENINE-DINUCLEOTIDE; BLUE-LIGHT PHOTORECEPTORS; COLI DNA PHOTOLYASE; TIME-RESOLVED FLUORESCENCE; ELECTRON-TRANSFER; ULTRAFAST DYNAMICS; AQUEOUS-SOLUTION; TRYPTOPHAN; ABSORPTION; Cryptochrome cry3; Cryptochrome mutant; Arabidopsis thaliana; Blue-light photoreceptor, DNA-photolyase, flavin adenine dinucleotide (FAD); Photocycle dynamics; Photo-induced charge transfer; FAD reduction and oxidation |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Alumni or Retired Professors > Group Alfons Penzkofer |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Sep 2020 05:45 |
| Last Modified: | 02 Sep 2020 05:45 |
| URI: | https://pred.uni-regensburg.de/id/eprint/28138 |
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